Determination of type specific antigenic reactivities and quantitation of murine mammary tumor virus by ELISA.

Type specific differences associated with the antigenic determinants of exogenous and endogenous murine mammary tumor viruses (MuMTVs) isolated from strain C3H(Jax) and ICRC were demonstrated by competition enzyme linked immunosorbent assay (ELISA). In this assay, highly purified intact MuMTV from the milk of strain C3H(Jax) was conjugated to the enzyme penicillinase using glutaraldehyde. IgG fraction of antiserum prepared against disrupted C3H (Jax) MuMTV was used in the competition ELISA. The assay was highly reproducible, specific to MuMTV antigens and detected 6-9 ng of the viral proteins. For competition, MuMTV preparations from corresponding endogenous MuMTV carrying subline C3H(Mect) and ICRCf were also used. The assay demonstrated the type specific antigenic reactivities inherent in the MuMTVs isolated from C3H(Jax) and ICRC strains of mice. The competition ELISA was also used to quantitate MuMTV specific proteins in tissue extracts and milk plasma.