Chromic Chloride: A Coupling Reagent for Passive Hemagglutination Reactions

Abstract

The passive hemagglutination procedure using a chromium chloride solution to bind antigens and antibodies to red cells has been investigated. The CrCl₃ method of coating red cells is rapid and simple, and serologic sensitivity and immunologic specificity are retained. The present studies showed that group O human red cells coated with antigen by the CrCl₃ procedure can be used in a number of serologic reactions. In particular, use of CrCl₃-treated cells as immunoadsorbent provides a rapid method for the preparation of monospecific antisera to human immunoglobulins. The immunoglobulin content of pathologic sera can be estimated by the degree to which the pathologic serum inhibits an appropriate agglutination system consisting of cells coated with γG-, γA- or γM-globulin by the CrCl₃ method and of homologous antibody. “Purified” immunoglobulin preparations can be assessed for contamination by similar inhibition of agglutination of red cells coated with immunoglobulins by the CrCl₃ method.