Cross-reactive primary antibodies (also from VMRD) specific for HLA-DRa class II molecules of the major histocompatibility complex (MHC; 1 in 250; HLA-DRa, Clone TH14B), HLADQ class II MHC (1 in 250; HLA-DQ, Clone TH81A5), HLA-DP class II MHC (1 in 250; HLADP, Clone H42A) and class I molecules of the MHC (1 in 500; Clone H58A) were also employed.