Lewis typing of human bloodstains by enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-Le(a) and anti-Le(b).

The Lewis blood grouping of human dried bloodstains could be determined by an enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-Le(a) and anti-Le(b) antibodies with an avidin-biotin complex (ABC). The bloodstains aged 1 year were used as samples, and approximately 1 mg of the stains was enough to type each Lewis antigen reliably by this method. The Lewis substances of 106 individual stains were correctly typed regardless of their ABO blood group system.