Succinylation of hapten-protein conjugates facilitates coupling to erythrocytes by water soluble carbodiimide: preparation of stable and sensitive target cells for use in hemolytic assays.

A facile method is described for the preparation of haptenated sheep red blood cells (SRBC) for use as targets in hemolytic spot and plaque assays for the detection of anti-hapten antibody. The method involves the use of the water soluble 1-ethyl-3-(3-dimethyl-aminopropyl)carbodiimide (EDCI) as a reagent to couple hapten-succinyl-rabbit serum albumin conjugates to SRBC. The presence of the succinyl groups on such conjugates is shown to increase the efficacy of the resulting target cells, presumably by acting as a substrate for the EDCI and thus increasing the extent of coupling to SRBC.