HLA-A-SPECIFIC AND HLA-B-SPECIFIC MONOCLONAL-ANTIBODIES REACTIVE WITH FREE HEAVY-CHAINS IN WESTERN BLOTS, IN FORMALIN-FIXED, PARAFFIN-EMBEDDED TISSUE-SECTIONS AND IN CRYOIMMUNOELECTRON MICROSCOPY

The mAb HCA2 reacts preferentially with HLA-A locus heavy chains. Its reactivity contrasts with that of HC1O, a mAb with more pronounced specificity for HLA-B and -C heavy chains. Both HCA2 and HC1O were raised against free class I heavy chains of HLA-A and -B antigens respectlveiy, to obtain mAbs that wouid stiil react with denatured class I antigens, as they occur in Western biotting, conventional light microscopical analysis of formalin-fixed, paraffin- embedded sections, and cryo-lmmuno-eiectron microscopy. HCA2 and HC1O indeed retain strong reactivity with free class I heavy chains in Western blots. The HCA2 mAb In particular reacts in a locus-specific manner by biochemical criteria. Conditions are described for use of HCA2 and HC1O in Immunohistochemlcal staining of formalin-fixed, paraffin-embedded sections. HCA2 and HC1O also produce strong reactivity in immuno-electron microscopy. Their use allows the determination of tissue and subcellular distribution of class I antigens. © 1990 Oxford University Press.