Directional coupling of synthetic peptides to poly-L-lysine and applications to the ELISA

Synthetic peptides are increasingly being used as antigens to generate highly specific antisera. Screening the antipeptide sera by enzyme-linked immunosorbent assay (ELISA) can suffer from carrier crossreactivity or lack sensitivity due to poor adsorption or presentation of the peptides. In this work we describe a procedure utilizing a heterobifunctional crosslinker to effect the directional coupling of synthetic peptides to poly-L-lysine preadsorbed to microtiter plates. Plates prepared by this method conferred precision, sensitivity, and specificity to an ELISA for antipeptide antisera. In a competitive ELISA format this method permitted detection of specific peptides to 3.7 x 10(-10) M and provided an assay sensitive to protein structure in solution.