Passive Hemagglutination Procedures for Protein and Polysaccharide Antigens Using Erythrocytes Stabilized by Aldehydes

Summary Chicken, sheep and rabbit erythrocytes were stabilized with formaldehyde, pyruvic aldehyde or both, for use in passive hemagglutination reactions. Bovine serum albumin, insoluble BSA, ovalbumin, rabbit γ-globulin, chicken γ-globulin, bovine γ-globulin, E. coli endotoxin, acetylated endotoxin, de-esterified endotoxin, de-esterified and bromacetylated endotoxin, succinylated endotoxin and synthetic polyglucose were found to adsorb firmly on the stabilized cells. For optimal coating of stabilized cells with antigens, critical factors included pH, antigen concentration and the duration of contact with antigen. These conditions differed somewhat from one antigen to another. Coated cells could be stored frozen or lyophilized. Approximately 1 × 10-7 to 1 × 10-8 mg of anti-BSA antibody were detected by using rabbit erythrocytes coated with BSA. This level of sensitivity compares favorably with tannic acid or BDB procedure for cell coating. Antiglobulin tests were applicable in all of the cases tested and were found to increase the hemagglutination titers 10- to 30-fold.