The GA-R2 (also known as HIR2) monoclonal antibody specifically binds to CD235a and CD235b. CD235a is also known as Glycophorin A (GYPA, GPA, GLPA), Sialoglycoprotein alpha, MN sialoglycoprotein, or PAS-2. CD235b is otherwise known as Glycophorin B (GYPB, GPB, GLPB), Sialoglycoprotein delta, SS-active sialoglycoprotein, or PAS-3. CD235a and CD235b are type I transmembrane sialoglycoproteins that are expressed on human erythrocytes, erythroid precursor cells and certain leukemic cell types. CD235a carries blood group M and N antigens, whereas CD235b contains S, s, and U antigens. This antibody is useful for the identification and characterization of erythrocytes, certain myeloid leukemic cell types, and studies of erythroid cell development and infectious diseases with erythrocyte involvement. Glycophorins may play a role in preventing cell agglutination.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.