Protein instability index calculator
Calculate the instability index of protein sequences. Upload a FASTA file or paste your protein sequences below to get the instability index values.
Input (Protein sequences)
FASTA
Click to upload or drag and drop
FASTA file (.fasta, .fas, .fa, .txt)
Max size: 50MB
Output options
Instability index
Numbers
About instability index calculation
The instability index predicts protein stability in a test tube:
- • Method: Based on dipeptide instability weights (DIWV)
- • Formula: II = (10/L) × Σ DIWV(AiAi+1)
- • Stable: II < 40 (stable in vitro)
- • Unstable: II ≥ 40 (unstable in vitro)
- • Reference: Guruprasad et al. (1990)