Protein Isoelectric Point calculates the theoretical pI (isoelectric point) for the protein sequence you enter. Use Protein Isoelectric Point when you want to know approximately where on a 2-D gel a particular protein will be found.

Paste the raw sequence or one or more FASTA sequences into the text area below. Input limit is 200000 characters.

  • Add copies of to the above sequence.
  • Use pK values from


P. Stothard. The sequence manipulation suite: JavaScript programs for analyzing and formatting protein and DNA sequences. Biotechniques 2000; 28: 1102, 1104.