Affinity of antibodies to MUC1 antigens.

The binding affinity of a monoclonal antibody to its ligand has been often used as a qualitative and quantitative measure for the specificity of the antibody. The aim of this paper was to assess the affinity of binding to recombinant and synthetic MUC1 peptides of 52 monoclonal antibodies as part of the ISOBM TD-4 Workshop. Affinity of binding was assessed using a surface plasmon resonance biosensor (BIAcore). The monoclonal antibodies exhibited variable affinity to MUC1 peptides, and overall 25/52 antibodies showed significant binding to the test peptides with affinities ranging from 2.4 x 10(6) to 3.1 x 10(8) M-1. Affinities calculated by analysis of kinetic biosensor data agreed well with affinities determined by equilibrium binding analysis of radiolabelled antibodies. The affinity measurements may provide help when determining the use of various monoclonals in tumour biology research.