Human Subgroup Assignment

This page allows you to identify the subgroup of a human light or heavy chain. The code which does the actual assignments was kindly supplied by Sophie Deret ( ) and it normally features as part of her Subim program. (You can also download from

The method is described in Deret, S. et al (1995), SUBIM: a Program for Analysing the Kabat Database and Determining the Variability Subgroup of a new Immunoglobulin Sequence, Comput Appl Biosci, 11, 435-439.

1st August 2018: This code was completely rewritten and some assignments may now change. The previous version of the code did not deal correctly with extensions at the N-terminus of the sequence potentially leading to incorrect assignments. N-terminal extensions of up to 20 residues are now handled correctly.

Enter the human amino acid sequence (1-letter code) of your light or heavy chain variable fragment:

Please enter your EMail address:

Commercial Use

Companies may use this public server, but need to be aware that data are not encrypted and it is not secure.

After trialing the system, companies should consider abYsis. A commercial licence will enable you to install a local version of this code together with an integrated database which can also store and analyse proprietary sequence and structure data.

For information on commercial licences, please contact the distributor Ebisu.