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Protein pI calculator
Paste a protein sequence and estimate its isoelectric point — the pH at which the protein carries no net charge — by solving the charge balance over all ionisable groups. Essential for ion-exchange chromatography and 2D gel work.
0 bases · Spaces, line numbers and FASTA headers are removed automatically.
Result
Good to know
An estimate, with the pKa set shown
Calculated pI values depend on the pKa table used, which is why the result prints the exact set. Experimental pI (from isoelectric focusing) can differ, especially for proteins with buried residues or modifications.