Anti-human serum (COOMB’S Antisera) is an important diagnostic aid in determining the presence or absence of red blood cell antibody or components of human complement on red blood cells. Accordingly anti-human serum is used for compatibility testing, antibody detection, antibody identification, testing for the variant of the Rho (D) antigen (DU tests), and umbilical cord red blood cell testing. Anti-human serum may be used in the direct antiglobulin test and in the indirect antiglobulin test to detect antibodies and/or complement on red blood cells.
The procedures used with the reagent are based on the principle of heteroagglutinins directed against components of human serum as originally described by Moreschin and agglutination as described by Landsteiner.Normal human red blood cells, in the presence of antibody directed toward an antigen they possess, may become sensitize but fail to agglutinate due to the particular nature of the antigen and antibody involved. Anti-human serum will react with red cells sensitized with gamma globulin (red blood cell antibody) or components of human complement and cause agglutination of the red blood cells.