NEW! You can download the results of your analysis as a PDF file. You can now also enter sequence name / ID which will also appear in your PDF report.
NEW! See below for some helpful links to other protein analysis tools

Protein Parameters

Welcome to the Protein Parameters web app for analysing protein sequences. The program performs most of the same functions as the Expasy ProtParam tool, but also allows you to enter a DNA sequence for translation. You can also enter your protein OD280nm once your Protein Parameters have been determined to instantly calculate your protein concentration. Simply select the sequence type (DNA or Protein), enter your sequence and click "Submit".

Use single letter code for proteins

You can successively enter multiple OD values if required.

Click to download results as a pdf file


Extinction coefficient

Gill, S.C. and von Hippel, P.H. (1989) Calculation of protein extinction coefficients from amino acid sequence data. Anal. Biochem. 182:319-326(1989). PubMed: 2610349

Aliphatic Index

Ikai, A.J. (1980) Thermostability and aliphatic index of globular proteins. J. Biochem. 88, 1895-1898. Pubmed: 7462208


Kyte, J. and Doolittle, R.F. (1982) A simple method for displaying the hydropathic character of a protein. J. Mol. Biol. 157, 105-132. PubMed: 7108955


Bjellqvist, B., et al. The focusing positions of polypeptides in immobilized pH gradients can be predicted from their amino acid sequences. Electrophoresis 1993, 14, 1023-1031. PubMed: 8125050

Bjellqvist, B., et al. Reference points for comparisons of two-dimensional maps of proteins from different human cell types defined in a pH scale where isoelectric points correlate with polypeptide compositions. Electrophoresis 1994, 15, 529-539. PubMed: 8055880

Wikipedia amino acid pKa values: Wikipedia

The Expasy ProtParam web tool can be found at