PRESERVATION OF ANTIGEN-COATED SHEEP ERYTHROCYTES BY FREEZING FOR USE IN INDIRECT HEMAGGLUTINATION PROCEDURE

Abstract
Preservation of sheep erythrocytes, coated with various protein and lipopolysaccharide antigens, was accomplished by rapid freezing and storage at -70C in a dextrose-lactose solution. The stored cells were tested at intervals in an indirect hemagglutination procedure. Sensitivity of these cells was maintained, and antibody titers were consistently reproducible throughout the period of testing. These observations suggest that sheep erythrocytes may be coated with a variety of antigens and may be employed satisfactorily in an indirect hemagglutination test, even after storage at -70C for a period up to 6 months.