MHC Class 2, I-A, Rt1.Bu

Recognizes a polymorphic determinant of rat Ia antigen (RT1.Bu) present on Lewis, Wistar and AO strain rats, but not RN, DA or PVG/c strains. The antibody crossreacts with mouse strains (MHC haplotypes b and s) and analysis of recombinant mouse strains showed that the determinants mapped to the I-A region. It recognizes Ia antigens on B cell, dendritic cells and certain epithelial cells. It is particularly useful for distinguishing Ia positive cells from different rat strains, eg for recognizing cells of donor origin in bone marrow reconstituted radiation chimeras.