MHC Class 2, I-A (FITC)

Recognizes a polymorphic determinant of rat Ia antigen present on Lewis, Wistar and AO strain rats but not BN, DA or PVG/c strains (1,2). 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 la antigens on B-cells, dendritic cells and certain epithelial cells (1, 3, 4). It is particularly useful for distinguishing la positive cells from different rat strains, eg for recognizing cells of donor origin in bone marrow reconstituted radiation chimeras (3,4.