Abstract
Protein A was applied as a reagent for the secondary reaction in ELISA (protein A-ELISA). Mouse hepatitis virus antibody in 6 prevalent mouse strains or stocks reared in a MHV-contaminated room was effectively detected by protein A-ELISA, whereas significant strain differences in the antibody detection rate were demonstrated using the complement fixation test. C57BL/6 mice were particularly reactive in the protein A-ELISA test.