# ProteinIQ guides

> In-depth guides on protein analysis, molecular docking, drug discovery, and bioinformatics tools.

Topics: [Protein guides](https://proteiniq.io/guides/category/proteins.md) · [Genetics guides](https://proteiniq.io/guides/category/genetics.md) · [Protein structure guides](https://proteiniq.io/guides/category/structures.md) · [Protein design guides](https://proteiniq.io/guides/category/design.md) · [Molecular docking guides](https://proteiniq.io/guides/category/docking.md) · [Antibody guides](https://proteiniq.io/guides/category/antibodies.md) · [Drug discovery guides](https://proteiniq.io/guides/category/drugs.md) · [Cell biology guides](https://proteiniq.io/guides/category/cells.md)

- [The best free molecular dynamics software in 2026](https://proteiniq.io/guides/molecular-dynamics-software): The best molecular dynamics engines are free: GROMACS, AMBER, OpenMM, NAMD and LAMMPS run most published simulations. We compare them on what each is best at, GPU speed on standard benchmarks, licenses and what a run needs from you, and say where Schrödinger's Desmond still earns its price.
- [The best phylogenetic tree software in 2026](https://proteiniq.io/guides/phylogenetic-tree-software): The best phylogenetic tree programs are free and open source: IQ-TREE, RAxML-NG and FastTree for maximum likelihood, MrBayes and BEAST X for Bayesian trees, and MEGA for a point-and-click desktop. We compare them on benchmarks, licenses and what each needs from you, show the same primate tree built three ways, and cover the viewers and the one paid suite worth considering.
- [The best protein structure prediction software in 2026](https://proteiniq.io/guides/protein-structure-prediction-software): The best protein structure prediction software is mostly free: AlphaFold2 with ColabFold, ESMFold, Boltz-2, Chai-1, SWISS-MODEL and BioEmu each do one job better than the rest. We compare them on accuracy, what they need from you and their licenses, and explain when AlphaFold 3 is worth its restrictions.
- [The best free molecular docking software in 2026](https://proteiniq.io/guides/molecular-docking-software): The best docking programs are free and open source: AutoDock Vina, GNINA, DiffDock, DynamicBind and Boltz-2 cover most of what academic and industry groups dock today. We compare them on what each is best at, how accurate the published benchmarks say they are, what they need from you, and where Schrödinger's Glide still earns its price.
- [The best free ChemDraw alternatives in 2026](https://proteiniq.io/guides/chemdraw-alternatives): ACD/ChemSketch Freeware was discontinued in January 2026 and Marvin's free academic licenses ended in July, so the usual answers to "is there a free ChemDraw?" no longer work. We compare the free chemical drawing tools that remain, online and desktop, plus one cheap paid option, on drawing, ChemDraw file exchange, search, properties and price.
- [ChemDraw on Mac, Linux and Chromebook: your options](https://proteiniq.io/guides/chemdraw-for-mac): ChemDraw runs natively on Apple silicon Macs, but only on macOS Sequoia and Tahoe, and several of its parts are Windows only. It does not install on Linux, ChromeOS or an iPad. We cover which ChemDraw version supports which macOS, how to download it for a Mac, what Linux and Chromebook users do instead, ChemDraw+ in the browser, and free browser drawers that open ChemDraw files.
- [ChemDraw price and licenses explained](https://proteiniq.io/guides/chemdraw-price): ChemDraw costs $700, $1,355 or $1,415 per person per year, depending on the tier, and has been subscription-only since 2025. We explain what each tier adds, how named-user, academic and site licenses work, what students pay, what is still free, and when a free drawer is enough.
- [Chemical file formats compared: MOL, SDF, MOL2, CDX, SMILES and InChI](https://proteiniq.io/guides/chemical-file-formats): MOL, SDF, MOL2, PDB, PDBQT, CDX, CDXML, KET, SMILES and InChI all describe molecules, but they disagree about coordinates, bond orders, charges, stereochemistry and how many structures a file holds. We compare them on one molecule, show which format fits which job, and list what each conversion can and cannot recover.
- [ChemSketch Freeware is gone: what to use instead](https://proteiniq.io/guides/chemsketch-alternatives): ACD/ChemSketch Freeware was discontinued in January 2026, when Revvity Signals bought ACD/Labs, and the paid version is no longer sold to new customers. What you can still do with the copy you have, how to get your .sk2 drawings out before you lose access, and which free and paid tools replace each thing ChemSketch did.
- [How to draw chemical structures online for free](https://proteiniq.io/guides/draw-chemical-structures-online): Draw a chemical structure in your browser with no install or account: find a known compound by name, CAS number or SMILES, draw a new one with rings, bonds and keyboard shortcuts, read its formula and properties, and export it as SMILES, MOL, ChemDraw CDXML or an image.
- [From a drawn molecule to a docking result](https://proteiniq.io/guides/drawing-to-docking): Draw or look up a ligand in SketchIQ, check its charge and stereocentres, send it to AutoDock Vina with one click, pick a receptor and box, then open the best pose back in the drawer to make the next analog. Worked through with imatinib and c-Abl kinase.
- [InChI, InChIKey, SMILES and CAS numbers: what each identifier is for](https://proteiniq.io/guides/inchi-inchikey-smiles-cas): InChI, InChIKey, SMILES, CAS Registry Numbers and PubChem CIDs all point at a chemical, but they answer different questions. We take one drug family apart to show how InChI layers, InChIKey hashing and collisions, canonical and isomeric SMILES, the CAS check digit and PubChem CIDs behave, and which identifier to use for search, databases, ordering and papers.
- [Molecular weight vs exact mass, and how to calculate HRMS ions](https://proteiniq.io/guides/molecular-weight-exact-mass): Caffeine weighs 194.19 g/mol on a balance, has a monoisotopic exact mass of 194.0804, and shows up in a positive-mode HRMS spectrum at m/z 195.0877. We work through all three numbers by hand, show how isotopes, salts and hydrates change them, and give the formulas for [M+H]+, [M+Na]+ and [M−H]− with the electron mass included.
- [How to open a CDX or CDXML file without ChemDraw](https://proteiniq.io/guides/open-cdx-cdxml-without-chemdraw): A .cdx or .cdxml file is a ChemDraw drawing. Open it free in your browser with SketchIQ, then copy the SMILES or save it as MOL, SDF, PNG or a new ChemDraw file. We tested real files from ChemDraw 5.1 to 23.1 and list what survives conversion and what does not.
- [How to predict pKa online for free](https://proteiniq.io/guides/predict-pka-online): Predict pKa for free by drawing a molecule in SketchIQ and clicking Predict pKa: MolGpKa runs in your browser and returns a pKa for each acidic and basic site, the net charge, the major form and logD at any pH. We explain why pKa matters for drugs, how prediction works, and how accurate it is, with 27 drugs tested against measured values.
- [How to make publication-quality chemical structure images](https://proteiniq.io/guides/publication-quality-chemical-structures): Draw every structure with the same bond length, line width and font, then export a vector file or a bitmap with enough pixels for its printed size. Here are the ACS Document 1996 settings, what ACS, RSC, Elsevier, Wiley and Nature ask for, and how to do it free in SketchIQ.
- [How to draw stereochemistry: wedges, dashes and R/S labels](https://proteiniq.io/guides/stereochemistry-wedges-dashes): Use a solid wedge for a bond toward you and a hashed wedge for one pointing away, with the narrow end on the stereocenter, and leave unknown centers plain. We explain where wedges go, how CIP rules turn a drawing into R, S, E or Z, how to mark racemic and relative stereochemistry, and how to check every label in a free drawer.
- [What is a CIF file? Small-molecule CIF and mmCIF explained](https://proteiniq.io/guides/cif-file): A CIF file is a plain-text Crystallographic Information File. Learn the difference between small-molecule CIF and macromolecular mmCIF, how data blocks and loops work, why the PDB replaced the PDB format with mmCIF, and how to convert between them.
- [Codon optimization: what it changes and when it helps](https://proteiniq.io/guides/codon-optimization): Codon optimization swaps synonymous codons so a gene matches its host, without changing the protein. It changes codon choice, GC content, restriction sites, repeats and mRNA folding near the start codon. It helps most when a gene comes from a distant species, and it can backfire when it tightens the start of the message or speeds up a protein that needs to fold slowly. A worked example rewrites human interleukin-2 for E. coli and scores it before and after.
- [Disulfide bonds in proteins: how they form and what they do](https://proteiniq.io/guides/disulfide-bonds): A disulfide bond is a covalent S-S link between the side chains of two cysteines, formed by oxidation of their thiol groups. Proteins make them in the endoplasmic reticulum and the bacterial periplasm, rarely in the cytosol. Learn the chemistry, the geometry measured in 941 high-resolution structures, why a cross-link stabilizes a protein, famous examples such as insulin, lysozyme and IgG, and how to find disulfides in a structure file or in the lab.
- [How to make a FASTA file](https://proteiniq.io/guides/how-to-make-a-fasta-file): Create a FASTA file in Notepad or TextEdit, convert text, Word, or Excel data to FASTA, download FASTA from NCBI or UniProt, and avoid the mistakes that make tools reject the file.
- [Kyte-Doolittle hydropathy scale and how to read a hydropathy plot](https://proteiniq.io/guides/kyte-doolittle-hydropathy): The Kyte-Doolittle hydropathy scale gives each amino acid a value from +4.5 (isoleucine) to −4.5 (arginine). Learn all 20 values, how Kyte and Doolittle derived them, how window size shapes a hydropathy plot, where the 19-residue window and 1.6 cutoff come from, how often that rule is right on the human proteome, and how to read peaks, valleys and GRAVY.
- [MM/PBSA vs MM/GBSA: how end-point binding free energies work](https://proteiniq.io/guides/mm-pbsa-vs-mm-gbsa): MM/PBSA and MM/GBSA estimate protein-ligand binding free energy from molecular dynamics snapshots. Learn the energy terms, how Poisson-Boltzmann and generalized Born solvation differ, single- versus three-trajectory protocols, the entropy term, and what benchmark studies say about accuracy.
- [What are the most acidic and basic amino acids?](https://proteiniq.io/guides/most-acidic-and-basic-amino-acids): Aspartic acid is the most acidic standard amino acid and arginine the most basic, by side-chain pKa. Values and charge at pH 7.4 for all seven ionizable side chains, and how folded proteins shift them.
- [Phylogenetic tree: what it shows and how to read one](https://proteiniq.io/guides/phylogenetic-tree): A phylogenetic tree is a hypothesis about how sequences or species descend from common ancestors. Learn the parts of a tree, how to read relatedness from common ancestors rather than tip order, rooted vs unrooted trees, cladograms, phylograms and chronograms, bootstrap and UFBoot support, the Newick format, and common misreadings, with a real primate tree built from nine mitochondrial genomes.
- [Post-translational modifications: types, examples and what they do](https://proteiniq.io/guides/post-translational-modifications): Post-translational modifications (PTMs) are covalent changes to a protein during or after its synthesis: phosphorylation, glycosylation, acetylation, methylation, ubiquitination, SUMOylation, lipidation, proteolytic cleavage, disulfide bonds and hydroxylation. Learn which residues each one targets, where in the cell it happens, how common it is in UniProtKB/Swiss-Prot, how it changes charge, mass, localization, stability and activity, and how mass spectrometry detects it.
- [Primer dimers: how they form, how to predict them and how to stop them](https://proteiniq.io/guides/primer-dimers): A primer dimer is a short PCR artifact made when two primers anneal to each other and the polymerase extends them. Learn why 3′ complementarity matters most, how dimers show up on gels, melt curves and no-template controls, how ΔG and Primer3's complementarity limits score them, and how to prevent and fix them, with a worked β-actin example.
- [Protein aggregation: causes, prediction and prevention](https://proteiniq.io/guides/protein-aggregation): Protein aggregation is the self-association of protein molecules into amorphous clumps, soluble oligomers or ordered amyloid fibrils. Learn why proteins aggregate, how aggregates are measured, what TANGO, AGGRESCAN, CamSol, Aggrescan3D, Protein-Sol and NetSolP predict from sequence and structure, and how formulation, mutations and expression conditions prevent it, with a worked Aggrescan3D run on transthyretin.
- [What is protein denaturation?](https://proteiniq.io/guides/protein-denaturation): Protein denaturation is the loss of a protein's secondary, tertiary and quaternary structure while its amino acid sequence and peptide bonds stay intact. Learn how heat, cold, pH, urea, SDS, alcohol and force unfold proteins, why most proteins are stable by only 5 to 15 kcal/mol, why Anfinsen's ribonuclease refolds but egg white does not, and how CD, fluorescence, DSC and DSF measure it.
- [Protein extinction coefficient and A280 concentration](https://proteiniq.io/guides/protein-extinction-coefficient): The molar extinction coefficient converts a protein's absorbance at 280 nm into a concentration through the Beer-Lambert law. It is predicted from the number of tryptophans, tyrosines and disulfide bonds with the Pace equation, which is reliable to a few percent for proteins with tryptophan and less so for proteins without it. Learn the mass and molar forms, a worked A280 example, and when A280 gives the wrong answer.
- [Isoelectric point of a protein: what pI means and how it is calculated](https://proteiniq.io/guides/protein-isoelectric-point): The isoelectric point (pI) is the pH at which a protein carries zero net charge. Learn how calculators find it from the sequence, why EMBOSS, ExPASy (Bjellqvist), Lehninger and IPC 2.0 give different values, how pI is distributed across the human proteome, and how to use it for isoelectric focusing, ion exchange and solubility.
- [What is a protein language model, and what is it used for](https://proteiniq.io/guides/protein-language-models): A protein language model is a neural network trained to predict amino acids from the rest of a sequence. Learn how ESM-2, ESM C, ESM3, ProtT5 and ProGen2 differ, what their embeddings and likelihoods are used for, how they compare with alignment-based methods like AlphaFold2, and which licences allow commercial use.
- [RNA secondary structure: dot-bracket notation and MFE explained](https://proteiniq.io/guides/rna-secondary-structure): RNA secondary structure is the set of base pairs an RNA strand forms with itself: stems, hairpins, bulges, internal loops and multiloops. Learn how dot-bracket notation encodes it, what the minimum free energy (MFE) means in the nearest-neighbor model, and how accurate thermodynamic prediction is.
- [SDF file format: how SDF and MOL files work](https://proteiniq.io/guides/sdf-file): An SDF (structure-data file) stores one or more small molecules as MDL molfiles, each followed by named data fields and a line of four dollar signs. Learn the molfile layout line by line, V2000 vs V3000, 2D vs 3D records, and how SDF compares with MOL2 and PDBQT for docking.
- [SMILES notation: how to read and write SMILES strings](https://proteiniq.io/guides/smiles-notation): SMILES (Simplified Molecular Input Line Entry System) writes a molecule's atoms and bonds as one line of text, such as CC(=O)Oc1ccccc1C(=O)O for aspirin. Learn the grammar with worked drug examples, how @, @@, / and \ encode stereochemistry, why canonical SMILES differ between databases, and how SMILES compares with InChI and SELFIES.
- [How many bispecific antibodies are approved?](https://proteiniq.io/guides/approved-bispecific-antibodies): By our count of agency records, 25 bispecific antibodies had been approved by the FDA, the EU, China or Japan by October 29, 2026. The FDA had approved 15, the EU 16, China 17 and Japan 12.
- [How many covalent drugs are approved?](https://proteiniq.io/guides/approved-covalent-drugs): A covalent drug forms a chemical bond with its target. ProteinIQ checked 2,104 approved small-molecule drugs in ChEMBL 37 and found 173 that act this way, 8.2% of the set, and 36 (1.7%) that were designed as targeted covalent drugs. Published counts of 50 to 128 differ mainly in whether beta-lactams and DNA alkylators are included.
- [How many oligonucleotide drugs are approved?](https://proteiniq.io/guides/approved-oligonucleotide-drugs): The FDA has approved 25 oligonucleotide drugs since 1998, and 21 are still sold in the US. Adding Europe and Japan gives 26. Full list of antisense, siRNA and aptamer drugs with a free CSV, checked October 29, 2026.
- [How many radiopharmaceutical therapies are approved?](https://proteiniq.io/guides/approved-radiopharmaceutical-therapies): The FDA has approved 11 radiopharmaceutical therapies since 1957, and 6 are approved today. Lutetium-177 dotatate gained two copies in September 2026. ClinicalTrials.gov lists 1,041 therapy trials, led by lutetium-177. Full list and CSVs, checked October 29, 2026.
- [What clashscore means and what counts as good](https://proteiniq.io/guides/clashscore): Clashscore is the number of serious all-atom overlaps, 0.4 Å or more, per 1,000 atoms of a structure. See what counts as a clash, typical values by resolution across 112,000 PDB entries, and how to fix a high score.
- [How many drug targets are there?](https://proteiniq.io/guides/drug-targets): ProteinIQ counted 809 molecular targets behind 2,205 approved drugs in ChEMBL 37: 611 in humans and 179 in pathogens. GPCRs carry 22% of those drugs; the often quoted 34% uses a smaller FDA list.
- [How many antibody-drug conjugates are FDA approved?](https://proteiniq.io/guides/fda-approved-adcs): The FDA has approved 15 antibody-drug conjugates, and all 15 are licensed today, including Mylotarg and Blenrep, which were withdrawn and later re-approved. Adding Europe and China gives 21. Full list and CSV, checked October 29, 2026.
- [How many peptide drugs are FDA approved?](https://proteiniq.io/guides/fda-approved-peptide-drugs): The FDA has approved 98 peptide drugs of 2 to 50 amino acids, and 77 are still marketed in the US. Leaving out antibiotics made by microbes gives 79; adding the insulins gives 106. Full list, GLP-1 family and free CSV, checked October 29, 2026.
- [GNINA CNN score vs CNN affinity: what each number means](https://proteiniq.io/guides/gnina-cnn-score): GNINA's CNN pose score is the probability that a docked pose lies within 2 Å of the true pose. CNN affinity is a predicted pK, and the empirical score is a Vina-style kcal/mol value. Learn how to read, threshold and combine them.
- [How much DNA do humans share with pigs?](https://proteiniq.io/guides/human-pig-dna-similarity): Not 98%. About half of the human genome aligns with pig DNA, aligned coding letters match at 86.7%, and a typical pig protein is 89.1% identical to the human one, against 99.3% for chimpanzees.
- [Human vs humanized vs chimeric antibodies: the origin of every FDA-approved antibody](https://proteiniq.io/guides/humanized-vs-fully-human-antibodies): Of 159 antibody products the FDA licensed by September 2026, 52% are humanized, 34% fully human, 9% chimeric and 5% murine, by ProteinIQ's label-by-label count. The fully human share has held near one-third since 2015. Free CSV.
- [IC50 vs Ki vs Kd: what each measures and how to convert them](https://proteiniq.io/guides/ic50-vs-ki): IC50 is the inhibitor concentration that halves activity in one assay. Ki and Kd are equilibrium dissociation constants that do not depend on the assay. Learn how the Cheng-Prusoff equation converts IC50 to Ki, when it fails, and why potency is compared as pIC50.
- [Lipinski's rule of five](https://proteiniq.io/guides/lipinski-rule-of-five): Lipinski's rule of five warns that oral absorption is less likely when a molecule breaks two or more of four limits: molecular weight above 500 Da, cLogP above 5, more than 5 hydrogen-bond donors and more than 10 acceptors. ProteinIQ found that 13% of 2,104 approved small-molecule drugs in ChEMBL 37 break two or more, and 28% break at least one.
- [mBER and ColabDesign metrics explained](https://proteiniq.io/guides/mber-metrics): What esm_score, i_ptm, i_pae, plddt, ptm, pae and seq_ent mean in mBER and ColabDesign output, which direction is better, and the cutoffs the mBER authors, BindCraft and other studies use.
- [How to open a PDB file](https://proteiniq.io/guides/open-pdb-file): Open a PDB file in your browser, in PyMOL, ChimeraX or VMD, or in a text editor on Windows and Mac, and learn to read its HEADER, ATOM and HETATM lines.
- [PAINS filters and pan-assay interference compounds](https://proteiniq.io/guides/pains-filters): PAINS filters are 480 substructure alerts that Baell and Holloway published in 2010 to flag compounds that often give false hits in screening assays. ProteinIQ ran them on 2,104 approved small-molecule drugs in ChEMBL 37: 122 (5.8%) trigger at least one alert, led by catechols such as levodopa and quinones such as doxorubicin.
- [PROTACs and molecular glue degraders in clinical trials](https://proteiniq.io/guides/protein-degraders-clinical-trials): By ProteinIQ's count, 102 targeted protein degraders had been dosed in human trials by October 29, 2026: 54 PROTACs, 28 molecular glue degraders, 7 other degraders and 13 of undisclosed type. Of these, 73 are still in development and two are approved.
- [Drug discovery statistics [2026]](https://proteiniq.io/guides/drug-discovery-statistics): Current drug discovery statistics on FDA novel drug approvals, Phase 1 success rates, development time and cost, biosimilars, cell and gene therapies, AAV products, CRISPR trials and AI-discovered drugs.
- [Drug discovery trends in 2026](https://proteiniq.io/guides/drug-discovery-trends): FDA's drug center approved 47 novel drugs by October 20, 2026, more than in all of 2025, while the global pipeline stopped growing for the first time in three decades and R&D returns came to depend on GLP-1 drugs.
- [How long do clinical trials take?](https://proteiniq.io/guides/how-long-do-clinical-trials-take): New drugs take a median 8.3 years from the first human study to FDA approval. Our analysis of 26,680 completed trials shows how long Phase 1, 2 and 3 trials last.
- [How long does a drug patent last?](https://proteiniq.io/guides/how-long-does-a-drug-patent-last): A drug patent lasts 20 years from filing in the US and EU. Extensions and regulatory exclusivity shift that date, and new US drugs average 12 to 15 years before the first generic.
- [How long does a western blot take?](https://proteiniq.io/guides/how-long-does-a-western-blot-take): A western blot takes 1 to 2 days with an overnight primary antibody at 4 °C, or about 5 to 7 hours when every step fits in one day. Compare step times for the gel, wet, semi-dry and dry transfer, blocking, antibodies and detection.
- [How long does mRNA last in a cell?](https://proteiniq.io/guides/how-long-does-mrna-last-in-a-cell): Most mRNAs in mammalian cells have half-lives of a few hours, and bacterial mRNAs last about 5 minutes. See medians by organism and method, the shortest- and longest-lived transcripts, and how long vaccine mRNA stays detectable.
- [How many antibiotics are there?](https://proteiniq.io/guides/how-many-antibiotics-are-there): The WHO classified 268 antibiotics used in humans in 2025: 93 Access, 145 Watch and 30 Reserve. Counts by class, recent approvals and other lists explain why other totals differ.
- [How many ATP are produced in glycolysis?](https://proteiniq.io/guides/how-many-atp-are-produced-in-glycolysis): Glycolysis makes 4 ATP and spends 2, a net gain of 2 ATP per glucose. See which steps spend and make ATP, what its 2 NADH are worth with and without oxygen, and why glycogen gives 3.
- [How many ATP are produced in the Krebs cycle?](https://proteiniq.io/guides/how-many-atp-are-produced-in-the-krebs-cycle): One turn of the Krebs cycle makes 1 ATP or GTP, 3 NADH and 1 FADH2. Per glucose it turns twice: 2 ATP directly, or about 20 once oxidative phosphorylation spends its NADH and FADH2.
- [How many chromosomes do humans have?](https://proteiniq.io/guides/how-many-chromosomes-do-humans-have): Humans have 46 chromosomes in 23 pairs, and sperm and eggs have 23. See which cells have 0, 92 or more, how chromatids are counted, and why apes have 48.
- [How many FDA-approved drugs are there?](https://proteiniq.io/guides/how-many-fda-approved-drugs): By our count of the FDA's October 2026 Drugs@FDA data, 26,899 approved drug products are currently marketed as prescription or OTC medicines, containing about 2,170 active ingredients. CDER has approved 1,434 novel drugs since 1985.
- [How many medicines are there in the world?](https://proteiniq.io/guides/how-many-medicines-are-there-in-the-world): There is no single worldwide count of medicines. DrugBank lists 4,815 approved drugs and 19,879 total drug entries, while the 2025 WHO Essential Medicines List contains 523 medicines.
- [How many peptide bonds are in a peptide?](https://proteiniq.io/guides/how-many-peptide-bonds-in-a-peptide): A linear peptide has one fewer peptide bond than amino acid residues, so a tripeptide has 2. See worked counts for insulin, cyclic peptides and glutathione, and what a peptide bond is.
- [How many RNA polymerases do eukaryotes have?](https://proteiniq.io/guides/how-many-rna-polymerases-do-eukaryotes-have): Eukaryotes have three nuclear RNA polymerases: Pol I makes ribosomal RNA, Pol II makes mRNA and Pol III makes tRNA and 5S rRNA. Land plants add Pol IV and Pol V, and mitochondria and chloroplasts carry their own enzymes.
- [How much DNA do cousins share?](https://proteiniq.io/guides/how-much-dna-do-cousins-share): First cousins share 12.5% of their DNA by descent on average, about 866 cM in the Shared cM Project. Second cousins share 3.125%, third cousins 0.78% and double first cousins 25%, and some third cousins share none.
- [How much DNA is needed for sequencing?](https://proteiniq.io/guides/how-much-dna-is-needed-for-sequencing): Most sequencing libraries start from 1 ng to 1 µg of DNA: about 10 ng for an amplicon panel, 100 to 500 ng for an Illumina human genome, 500 ng to 1 µg for PacBio HiFi, and 100 ng to 1 µg for Nanopore.
- [How much is the pharmaceutical industry worth?](https://proteiniq.io/guides/how-much-is-the-pharmaceutical-industry-worth): Global medicine spending reached about 1.94 trillion US dollars in 2025. Compare how IQVIA, EFPIA and Evaluate measure the market, the largest drug companies by revenue, and what drives growth.
- [How much of the human genome is junk DNA?](https://proteiniq.io/guides/human-genome-junk-dna): About 1% of human DNA codes for protein and roughly 8 to 11% is under evolutionary constraint, leaving about 90% without a detectable function. ENCODE's 80% counted any biochemical activity.
- [How long does it take to sequence a human genome?](https://proteiniq.io/guides/human-genome-sequencing-time): The Human Genome Project took 13 years. Today a sequencer reads a human genome in about 13 to 48 hours, the research record from DNA to variants is under four hours, and clinical results take 2 days to 4 weeks.
- [How big is the human proteome?](https://proteiniq.io/guides/human-proteome-size): The human proteome has about 20,000 reference proteins, one per protein-coding gene, and about 94% of them have been detected. Isoforms and proteoforms raise the count far higher.
- [Which organisms have the largest and smallest genomes?](https://proteiniq.io/guides/largest-and-smallest-genomes): Genome sizes of different organisms, from a 1,758-nucleotide circovirus and a 50,141-base-pair bacterial symbiont to the human genome and a 160-billion-base-pair fern.
- [AI drug discovery statistics [2026]](https://proteiniq.io/guides/ai-drug-discovery-statistics): AI drug discovery statistics for 2026: 117 AI-enabled drugs had entered clinical trials by mid-2025, three computationally designed drugs are in Phase 3 or under FDA review, and none is approved yet. Plus FDA submissions, funding, and the data models train on.
- [What is the molecular weight of an antibody?](https://proteiniq.io/guides/antibody-molecular-weight): A typical IgG antibody weighs about 150 kDa, its Fc and Fab fragments about 50 kDa each, and pentameric IgM about 970 kDa. Compare every class, chain and fragment.
- [Antibody variable regions: VH, VL, CDRs and frameworks](https://proteiniq.io/guides/antibody-variable-regions): VH and VL domains, the six CDRs and eight framework regions they contain, how Kabat, Chothia and IMGT draw CDR boundaries, and how V(D)J recombination and somatic hypermutation create variable-region diversity.
- [How much does drug development cost?](https://proteiniq.io/guides/drug-development-cost): Independent studies put the cost of developing a new drug near 0.7 to 1.3 billion US dollars once failures and capital costs are counted; industry-based estimates reach 2.6 to 2.7 billion. Here is what each figure includes, with costs by phase, therapeutic area and drug type.
- [How many druggable genes are there?](https://proteiniq.io/guides/druggable-genome): About 4,500 human genes are considered part of the druggable genome. A major analysis counted 4,479 drugged or druggable genes, equal to 22% of protein-coding genes.
- [Fab and Fc regions of an antibody: structure and function](https://proteiniq.io/guides/fab-and-fc-regions-of-an-antibody): The two Fab arms of an antibody bind antigen, and the Fc stem recruits immune cells, complement and the FcRn recycling receptor. Compare their domains, size and functions, how papain and pepsin separate them, and why the split matters for therapeutic antibodies.
- [How long does DNA last?](https://proteiniq.io/guides/how-long-does-dna-last): DNA can last months on an outdoor surface, centuries in buried bone, and about 2 million years in frozen sediment. Temperature, water, sunlight, and microbes set the pace far more than age does.
- [How long does DNA replication take?](https://proteiniq.io/guides/how-long-does-dna-replication-take): Human cells copy their DNA in about 8 hours, while E. coli copies its chromosome in about 40 minutes. See fork speeds, origin counts and replication times by organism.
- [How long does PCR take?](https://proteiniq.io/guides/how-long-does-pcr-take): A PCR machine usually runs for 45 minutes to 2 hours. Compare standard, fast, qPCR, and RT-qPCR run times, step times and extension rates per kilobase, and how long a PCR test result takes.
- [How many amino acids are in hemoglobin?](https://proteiniq.io/guides/how-many-amino-acids-are-in-hemoglobin): Adult hemoglobin A contains 574 amino acids in four chains. Fetal, A2 and embryonic hemoglobins have the same total, and counts of 578 include the methionine each chain starts with.
- [How many amino acids are in insulin?](https://proteiniq.io/guides/how-many-amino-acids-are-in-insulin): Human insulin has 51 amino acids in two chains, 21 in the A chain and 30 in the B chain. Here are both sequences, the 110-residue precursor and how analogs differ.
- [How many atoms are in the human body?](https://proteiniq.io/guides/how-many-atoms-in-human-body): A 70-kilogram adult contains about 7 octillion atoms. Roughly 62% are hydrogen, 24% oxygen, 12% carbon, and 1% nitrogen, and the total scales with body weight at about 100 septillion atoms per kilogram.
- [How many ATP are produced in cellular respiration?](https://proteiniq.io/guides/how-many-atp-are-produced-in-cellular-respiration): Aerobic respiration yields about 30 to 32 ATP per glucose under modern accounting, not the older 36 to 38. The shuttle that carries glycolytic NADH into mitochondria decides between 30 and 32.
- [How many ATP are produced in oxidative phosphorylation?](https://proteiniq.io/guides/how-many-atp-are-produced-in-oxidative-phosphorylation): Oxidative phosphorylation makes about 26 to 28 ATP per glucose, or 2.5 ATP per NADH and 1.5 per FADH2. Proton counting explains the fractions and why older textbooks say 34.
- [How many ATP does beta oxidation produce?](https://proteiniq.io/guides/how-many-atp-does-beta-oxidation-produce): Beta oxidation makes no ATP directly. Each round yields about 4 ATP through its NADH and FADH2, and complete oxidation of palmitate yields 106 net ATP, or 129 with older ratios.
- [How many bacteria are in the human body?](https://proteiniq.io/guides/how-many-bacteria-are-in-the-human-body): The human body carries about 38 trillion bacterial cells, nearly all in the colon, with a combined mass of about 0.2 kg. That is roughly 1.3 bacteria per human cell, not the 10:1 often quoted.
- [How many cell types are in the human body?](https://proteiniq.io/guides/how-many-cell-types-are-in-the-human-body): Modern censuses count about 400 major human cell types, twice the textbook figure of 200. Sorting cells by gene activity splits them into thousands of subtypes, 3,313 in the adult brain alone.
- [How many cells are in the human body?](https://proteiniq.io/guides/how-many-cells-are-in-the-human-body): An adult human body has roughly 30 to 37 trillion human cells. The latest census puts a 70 kg man at 36 trillion, a 60 kg woman at 28 trillion and a 10-year-old child at 17 trillion.
- [How many codons are there?](https://proteiniq.io/guides/how-many-codons-are-there): There are 64 codons in the standard genetic code. Sixty-one specify the 20 standard amino acids, and three, UAA, UAG, and UGA, are stop codons.
- [How many CpG sites are in the human genome?](https://proteiniq.io/guides/how-many-cpg-sites-in-human-genome): ProteinIQ counted 29.4 million CpG sites in the GRCh38 human reference genome and 33.9 million in the complete T2T-CHM13 sequence, or twice as many CpG cytosines across both strands.
- [How many enzymes are in the human body?](https://proteiniq.io/guides/how-many-enzymes-are-in-the-human-body): Humans encode about 3,800 enzymes, not 75,000. Reviewed human enzyme proteins cover 1,560 classified reactions across seven enzyme classes.
- [How many genes are in a chromosome?](https://proteiniq.io/guides/how-many-genes-are-in-a-chromosome): A human chromosome carries about 800 protein-coding genes on average, from 61 on the Y chromosome to 2,016 on chromosome 1. See current counts for chromosomes 1 through 22, X, Y, and mitochondrial DNA.
- [How many mitochondria are in a cell?](https://proteiniq.io/guides/how-many-mitochondria-are-in-a-cell): A liver cell holds about 1,000 to 2,000 mitochondria, and many human cells hold hundreds. Egg cells have the most, about 100,000, heart muscle cells pack the most by volume, and mature red blood cells have none.
- [How many monoclonal antibodies are FDA approved?](https://proteiniq.io/guides/how-many-monoclonal-antibodies-are-fda-approved): By our count of the FDA Purple Book, the FDA had licensed 159 monoclonal antibody products by September 2026, 150 of them still active. The broader published total of 169 through 2025 also counts Fc fusion proteins.
- [How many NADH are produced in glycolysis?](https://proteiniq.io/guides/how-many-nadh-are-produced-in-glycolysis): Glycolysis produces two NADH per glucose, both at step 6. See why the step runs twice, how many NADH each stage of respiration makes, and what happens to glycolytic NADH with and without oxygen.
- [How many neurons are in the human brain?](https://proteiniq.io/guides/how-many-neurons-are-in-the-human-brain): An adult human brain holds about 86 billion neurons, most of them in the cerebellum rather than the cortex. The popular figure of 100 billion was never measured.
- [How many platelets are in the human body?](https://proteiniq.io/guides/how-many-platelets-are-in-the-human-body): A typical adult man has about 2 trillion platelets: 1.3 trillion in circulating blood and 0.7 trillion held in the spleen. Each lives about 10 days.
- [How many ribosomes are in a cell?](https://proteiniq.io/guides/how-many-ribosomes-are-in-a-cell): Ribosome counts range from about a thousand in the smallest bacteria to more than 10 million in large human cells. Compare bacterial, yeast, plant and mammalian cells, ribosome size, translation speed and polysomes.
- [How many SNPs are in the human genome?](https://proteiniq.io/guides/how-many-snps-are-in-the-human-genome): A typical person carries 4 million to 5 million SNPs relative to the reference genome. About 10 million SNP sites are common worldwide, and dbSNP Build 157 lists 1.17 billion variant records.
- [How many viruses infect humans?](https://proteiniq.io/guides/how-many-viruses-infect-humans): The commonly cited estimate is about 270 known human-infecting viruses, but published totals range from 219 to 1,131 because studies use different evidence standards.
- [How many white blood cells are in the human body?](https://proteiniq.io/guides/how-many-white-blood-cells-are-in-the-human-body): About 23 to 55 billion white blood cells circulate in an adult's blood, but the whole body holds an estimated 1.8 trillion, most of them in bone marrow and lymph nodes.
- [How much DNA do siblings share?](https://proteiniq.io/guides/how-much-dna-do-siblings-share): Full siblings share about 50% of their DNA by descent on average, with measured pairs ranging from 37.4% to 61.7%. Fraternal twins share the same 50%, three-quarter siblings 37.5%, half-siblings 25% and identical twins virtually 100%.
- [How much DNA do humans share with chimpanzees?](https://proteiniq.io/guides/human-chimp-dna-similarity): Humans and chimpanzees match at 98.8% of aligned DNA letters, about 96% once insertions and deletions count, and about 85% under the strictest 2025 complete-genome rule, on which two human assemblies reach only 87%.
- [What percentage of the human genome is viral DNA?](https://proteiniq.io/guides/human-genome-viral-dna): About 9% of the human genome is viral DNA in the standard sense: inherited endogenous retrovirus sequences and their LTR relatives. ProteinIQ counted 9.1% of GRCh38 and 8.8% of the complete T2T-CHM13 genome, about 270 million bases.
- [How many types of proteins are in the human body?](https://proteiniq.io/guides/types-of-proteins-in-human-body): The human body makes nearly 20,000 distinct proteins, grouped into about seven functional types, yet only about a third of reviewed human proteins fit any of them. Collagen alone has 28 types.
- [Oligo analyzer comparison](https://proteiniq.io/guides/oligo-analyzer-comparison): Oligo analyzers and primer Tm calculators disagree by several degrees on the same primer, mostly because they assume different salt, Mg2+ and oligo concentrations. We compare the methods, corrections, hairpin and dimer checks, outputs and access of IDT OligoAnalyzer, Primer3, NEB, Thermo Fisher, Promega and ProteinIQ.
- [How many chromosomes do different species have?](https://proteiniq.io/guides/chromosome-counts-by-species): Dogs have 78 chromosomes, cats 38, humans 46 and chimpanzees 48. See which other animals share our 46, which have the most and fewest, and why counts differ.
- [How long is human DNA?](https://proteiniq.io/guides/how-long-is-dna): Each human cell holds about 2 m of DNA, and the whole body about 14 billion km, or 96 times the distance from Earth to the Sun. Each base pair adds 0.34 nm.
- [How many amino acids are there?](https://proteiniq.io/guides/how-many-amino-acids-are-there): Proteins use 20 standard amino acids. Selenocysteine and pyrrolysine bring the genetically encoded set across life to 22, nine are essential in the human diet, and about 500 occur in nature.
- [How many ATP are produced in fermentation?](https://proteiniq.io/guides/how-many-atp-are-produced-in-fermentation): Lactic acid and alcoholic fermentation each yield two net ATP per glucose. All of that ATP comes from glycolysis; the fermentation reactions add no more.
- [How many genes do humans have?](https://proteiniq.io/guides/how-many-genes-do-humans-have): Humans have about 20,000 protein-coding genes: 19,442 in GENCODE v50, 19,878 in Ensembl 116 and 19,838 in CHESS 3.1.3. With RNA genes and pseudogenes, GENCODE lists 78,733.
- [How much DNA do humans share with other animals?](https://proteiniq.io/guides/human-animal-dna-similarity): Pigs do not share 98% of human DNA. Measured the same way for every species, a typical pig protein is 89% identical to the human one, against 99% for chimpanzees and 86% for rats.
- [How much DNA do humans share with bananas?](https://proteiniq.io/guides/human-banana-dna-similarity): Yes, but not 50%. About 18% of human genes have a banana counterpart, their proteins are about 40% identical, and only 0.08% of the human genome matches.
- [How big is the human genome?](https://proteiniq.io/guides/human-genome-size): The human genome is about 3.1 billion base pairs long per chromosome set, or 6.3 billion per cell. Compare GRCh38, T2T-CHM13 and genome file sizes in GB.
- [What are the largest and smallest cells in the human body?](https://proteiniq.io/guides/largest-and-smallest-cells): The egg is the largest human cell at about 115 µm, sperm the smallest and a sensory neuron the longest. We also ranked 401 human cell types by mass.
- [What is the largest protein?](https://proteiniq.io/guides/largest-protein): PKZILLA-1 is the largest known protein at 45,212 amino acids. Titin is the largest human protein, and von Willebrand factor the largest in blood plasma.
- [How many proteins are there?](https://proteiniq.io/guides/number-of-proteins): Humans have about 20,000 proteins, one per protein-coding gene. UniProt lists 150 million protein records across all life. See what each count measures.
- [What is the smallest protein?](https://proteiniq.io/guides/smallest-protein): The smallest natural protein is an 11-amino-acid fruit fly peptide. In humans, MOTS-c has 16 and RPL41 has 25. The smallest unit of a protein is an amino acid.
- [AlphaFold license and commercial use](https://proteiniq.io/guides/alphafold-license-commercial-use): AlphaFold 2 and the AlphaFold Database allow commercial use, while the AlphaFold 3 weights and AlphaFold Server do not. See what each license allows and which models, including Boltz-2, Chai-1, RFdiffusion and ESM, companies can use.
- [DockQ score explained](https://proteiniq.io/guides/dockq): DockQ scores how closely a predicted protein complex matches a reference interface, from 0 to 1, with CAPRI cutoffs at 0.23, 0.49 and 0.80. Learn how it combines fnat, iRMSD and LRMSD, and how pDockQ estimates it with no reference.
- [What the MolProbity score and clashscore mean](https://proteiniq.io/guides/molprobity-score): The MolProbity score combines clashscore, rotamer outliers and Ramachandran favored residues into one number on the scale of crystallographic resolution. Learn what counts as good and how AlphaFold models score.
- [What is PAE, and how to read a PAE plot](https://proteiniq.io/guides/pae): PAE (predicted aligned error) is the pairwise confidence matrix that AlphaFold, Boltz and Chai-1 write next to a predicted structure. Learn how to read its blocks and stripes and use it for domains and interfaces.
- [How to read a Ramachandran plot](https://proteiniq.io/guides/ramachandran-plot): A Ramachandran plot shows the phi and psi backbone angles of every residue in a protein. Learn what the regions mean, what percentages a good structure has, and how to tell a model error from a strained residue.
- [What is RMSD, and what counts as a good value](https://proteiniq.io/guides/rmsd): RMSD is the average distance between matched atoms of two structures, in ångströms. Learn the formula, when to superimpose, and what values count as good for proteins, docked poses and molecular dynamics.
- [How to tell if a predicted protein structure is reliable](https://proteiniq.io/guides/structure-prediction-confidence): A predicted structure is reliable for a question when the scores that answer that question agree. Read pLDDT, PAE, pTM and ipTM in order, rescore interfaces with ipSAE, then check accuracy and geometry with DockQ and MolProbity.
- [What is a Vina score, and what counts as good](https://proteiniq.io/guides/vina-score): The AutoDock Vina score is a docking score in kcal/mol, not a measured binding energy. Learn what the output columns mean, why there is no universal good score, and how far Vina tracks experimental affinity.
- [How much do monoclonal antibodies cost?](https://proteiniq.io/guides/monoclonal-antibody-cost): Monoclonal antibody treatment averaged about $96,700 a year at US list price, from under $600 per preventive dose to over $12,500 per cancer dose. See how Medicare rates compare with manufacturing costs.
- [What is the most expensive element?](https://proteiniq.io/guides/most-expensive-elements): Rhodium is the most expensive element you can buy, at about $289 per gram in October 2026. Berkelium-249 and californium-252 cost far more, about $186 million and $60 million per gram.
- [How much does peptide synthesis cost?](https://proteiniq.io/guides/peptide-synthesis-cost): Custom peptides cost about $2 to $4.50 per amino acid crude and about $12 at over 95% purity. See how purity, length, scale and modifications change the price.
- [What is antibody engineering?](https://proteiniq.io/guides/what-is-antibody-engineering): Antibody engineering changes an antibody's sequence or structure to improve binding, reduce immunogenicity, tune effector function or create new formats. Learn the core techniques and computational workflows.
- [ipSAE explained](https://proteiniq.io/guides/ipsae): ipSAE is an interface confidence score for AlphaFold2, AlphaFold3 and Boltz that ignores disordered tails. Learn how it is calculated, why it beats ipTM and what 0.6 to 0.8 mean.
- [ipTM vs pTM: judging predicted complexes](https://proteiniq.io/guides/iptm-vs-ptm): pTM scores the whole predicted structure, while ipTM scores only how chains sit relative to each other. Learn what the 0.5, 0.6 and 0.8 cutoffs mean and why disordered tails lower ipTM.
- [What is pentobarbital?](https://proteiniq.io/guides/pentobarbital): Pentobarbital is a short-acting barbiturate. Its chemistry, how it acts on the brain, the 5-gram lethal injection dose, and why formulation and delivery matter.
- [What is pLDDT, and what counts as a good score](https://proteiniq.io/guides/plddt): pLDDT is the per-residue confidence score that AlphaFold, ESMFold and Boltz attach to predicted structures. Learn what the 90, 70 and 50 cutoffs mean and why a low score is not always a failure.
- [TM-score vs RMSD](https://proteiniq.io/guides/tm-score-vs-rmsd): RMSD and TM-score both compare two protein structures, but they answer different questions. Learn how each is calculated, what values count as good, and which one to use for prediction, fold search, docking or design.
- [Insulin prices and price history in the United States](https://proteiniq.io/guides/insulin-price-history): Trace U.S. insulin price history, the gap between list and net prices, the 2023–2024 price cuts, and what the Medicare insulin cap means in 2026.
- [Introns vs exons: what is the difference?](https://proteiniq.io/guides/introns-vs-exons): Exons are the parts of a gene kept in mature RNA, while introns are removed by splicing. Learn how much of a human gene is intron, why exons are not the same as coding DNA, and what happens when splicing fails.
- [15 most expensive drugs in the world](https://proteiniq.io/guides/most-expensive-drugs): Lenmeldy, a one-time gene therapy for metachromatic leukodystrophy, is the most expensive drug in the world at a US list price of $4.25 million. See the full ranking.
- [How many hemoglobin molecules are in a red blood cell?](https://proteiniq.io/guides/how-many-hemoglobin-molecules-in-a-red-blood-cell): A typical adult red blood cell holds about 270 million hemoglobin molecules, or about 1.1 billion heme groups. See how the count is calculated and why textbooks quote 250 to 300 million.
- [AlphaFold database statistics [2026]](https://proteiniq.io/guides/alphafold-statistics): AlphaFold DB lists 261,552,403 predicted models as of September 24, 2026. See the collection breakdown, human proteome coverage, and how the database compares with the PDB.
- [How much does it cost to sequence a genome?](https://proteiniq.io/guides/genome-sequencing-cost): A human genome costs about $220 to $450 at university sequencing labs and $399 to $595 as a consumer test. ProteinIQ's survey of US core facilities puts the median lab price at $419 before analysis.
- [What is Chai-2? De novo antibody design explained](https://proteiniq.io/guides/what-is-chai-2): Understand what Chai-2 designs, what its experimental hit rates mean, how access works, and which open tools address related antibody and protein binder tasks.
- [SignalP 6.0: official server, tutorial, and result interpretation](https://proteiniq.io/guides/what-is-signalp-6): SignalP 6.0 predicts N-terminal signal peptides, their class, biochemical regions, and cleavage sites using a protein language model and conditional random field.
- [How many red blood cells are in the human body?](https://proteiniq.io/guides/how-many-red-blood-cells-are-in-the-human-body): An average adult man has about 25 trillion red blood cells, and a reference woman about 20 trillion. See how many are in a drop of blood and how many are made each second.
- [Ozempic: What it is & latest statistics](https://proteiniq.io/guides/ozempic-statistics): Ozempic and GLP-1 statistics on use, weight loss, health outcomes, safety, sales and prices, with original sources and clearly defined comparisons.
- [Semaglutide vs tirzepatide](https://proteiniq.io/guides/semaglutide-vs-tirzepatide): Semaglutide (Ozempic, Wegovy) vs tirzepatide (Mounjaro, Zepbound): head-to-head weight loss and diabetes results, side effects and U.S. prices, with sources.
- [What is semaglutide?](https://proteiniq.io/guides/semaglutide): Semaglutide’s amino-acid sequence, molecular weight, GLP-1 mechanism and oral delivery, with our molecular calculations and audit of two PDB structures.
- [What percentage of clinical trials fail?](https://proteiniq.io/guides/clinical-trial-failure-rate): Historical estimates imply 86% to 93% attrition before approval. Our analysis of 33,667 registered trials separately measures early termination and reported stopping reasons.
- [How many genes are in mitochondrial DNA?](https://proteiniq.io/guides/how-many-genes-in-mitochondrial-dna): Human mitochondrial DNA has 37 canonical genes. Compare the standard count with evidence for additional small proteins and mtDNA copy numbers across tissues.
- [How many diseases are there? Counts, types, and stages](https://proteiniq.io/guides/how-many-diseases-are-there): Compare rare, neurodegenerative, heart, and liver disease counts, and distinguish fatty-liver grades from fibrosis, cirrhosis, hepatitis C, and liver cancer stages.
- [How many types of antibodies are there?](https://proteiniq.io/guides/how-many-types-of-antibodies-are-there): The human body has five antibody classes. Compare the structures, locations, functions, and subclasses of IgG, IgA, IgM, IgD, and IgE.
- [What are antibodies?](https://proteiniq.io/guides/what-are-antibodies): Learn what antibodies are, how they differ from antigens, how their structure enables binding, how B cells produce them, and how scientists analyze them.
- [What are monoclonal antibodies?](https://proteiniq.io/guides/what-are-monoclonal-antibodies): Learn what monoclonal antibodies are, how they differ from polyclonal antibodies, how hybridoma and recombinant production work, and how antibody specificity is validated.
- [What is the average size of a protein?](https://proteiniq.io/guides/average-protein-size): A typical protein is about 300–400 amino acids, 30–50 kDa, and 3–6 nanometers across when folded. See current proteome data and common examples.
- [How accurate is DNA sequencing?](https://proteiniq.io/guides/dna-sequencing-accuracy): DNA sequencing accuracy ranges from about 99% per raw base to above 99.9% for high-quality or consensus reads. The exact figure depends on the platform, chemistry, software, sample, and metric.
- [How many genomes have been sequenced?](https://proteiniq.io/guides/genbank-statistics): NCBI indexes 3.67 million current public genome assemblies. See bacterial, plant, human, species, and GenBank sequence counts for 2026.
- [How many types of RNA are there?](https://proteiniq.io/guides/how-many-types-of-rna-are-there): There are three major RNA types: mRNA, rRNA, and tRNA. rRNA is the most abundant by mass, tRNA is the smallest of the three, and mRNA can be the longest.
- [How many transcripts are in the human transcriptome?](https://proteiniq.io/guides/human-transcriptome-size): The current human reference annotation contains 644,292 transcript models, 278,455 of them protein-coding. Database records, expressed isoforms and RNA molecules are different counts.
- [What are the largest and smallest human genes?](https://proteiniq.io/guides/largest-and-smallest-human-genes): RBFOX1 is the largest human protein-coding gene by GENCODE v50 genomic span. MLDHR is the shortest under an HGNC-approved protein-coding filter, at 96 base pairs.
- [How long do proteins last in the body?](https://proteiniq.io/guides/how-long-do-proteins-last-in-the-body): Protein half-lives range from minutes to a lifetime. See measured medians, tissue differences, and why cycloheximide chase and isotope-labeling studies give different results.
- [How many protein interactions are in the human interactome?](https://proteiniq.io/guides/human-interactome-statistics): The human binary interactome probably contains hundreds of thousands to a few million protein-protein interactions. This guide separates estimates from experimental maps, curated evidence and predicted edges.
- [What is the most abundant protein in the human body?](https://proteiniq.io/guides/most-abundant-protein-in-human-body): Collagen is considered the most abundant protein in the human body by total mass, but actin, hemoglobin, and albumin lead under other definitions of abundance.
- [What's the most common amino acid?](https://proteiniq.io/guides/most-common-amino-acid): Leucine is the most abundant standard amino acid in reviewed Swiss-Prot protein sequences at 9.65%. The answer differs for collagen, individual proteomes, diets, and free amino acids.
- [Proteome sizes by species: protein counts compared](https://proteiniq.io/guides/proteome-sizes-by-species): Compare protein-coding genes, UniProtKB entries, and separate isoforms across 12 reference proteomes, with scope-aware examples of large and small proteomes.
- [Protein Data Bank statistics 2026: size and coverage](https://proteiniq.io/guides/rcsb-statistics): Current Protein Data Bank statistics for archive size, protein sequence coverage, experimental methods, growth, usage, computed models, and structure data formats.
- [What is the most abundant protein on Earth?](https://proteiniq.io/guides/most-abundant-protein-on-earth): Rubisco is considered the most abundant protein and enzyme on Earth, with an estimated global mass of about 0.7 gigatonnes. The ranking remains a well-supported claim rather than a complete census.
- [What is the fastest enzyme?](https://proteiniq.io/guides/fastest-enzyme): Catalase is the fastest enzyme by maximum turnover number. One catalase molecule can decompose an estimated 16 million to 44 million hydrogen peroxide molecules per second.
- [How long does it take to develop a vaccine?](https://proteiniq.io/guides/how-long-does-it-take-to-develop-a-vaccine): A successful new vaccine usually takes 10 to 15 years to develop. See how research, clinical trials, FDA review, cost, and the COVID-19, polio, mumps, MMR, and Ebola timelines compare.
- [How many nucleosomes are in a human cell?](https://proteiniq.io/guides/how-many-nucleosomes-are-in-a-human-cell): A typical diploid human cell contains about 30 million nucleosomes. See how that estimate is calculated and why a nucleosome can be described as containing 146, 166, or about 200 base pairs.
- [How many amino acids are in a complete protein?](https://proteiniq.io/guides/how-many-amino-acids-are-in-a-complete-protein): A complete protein supplies all nine essential amino acids in adequate amounts. An incomplete protein has too little of one or more, but usually still contains all nine.
- [58 E. coli statistics [2026]](https://proteiniq.io/guides/e-coli-statistics): Up-to-date E. coli statistics on the K-12 MG1655 reference genome, gene and protein counts, cell size, growth rate, ribosomes, mutation rate and U.S. STEC foodborne burden.