An enzyme linked immunosorbent assay (ELISA) for detecting IgG sensitized erythrocytes

This paper describes an Enzyme Linked Immunosorbent Assay (ELISA) for detecting IgG sensitized erythrocytes utilizing a commercially available anti-human IgG conjugated with alkaline phosphatase. Erythrocyte hemolysis in the assay was minimized by dissolving the p-nitrophenyl phosphate substrate in a carbonate-bicarbonate buffer. Nonspecific absorption of the enzyme conjugate to erythrocytes and glassware was reduced by adding 1% bovine serum albumin to wash solutions. Assay sensitivity was increased with greater concentrations of enzyme conjugate and erythrocytes in the incubation stage. The sensitivity of the described ELISA procedure is approximately equal to that of the standard antiglobulin test. Some possible future applications of ELISA in the blood bank are discussed.