The WT.3 monoclonal antibody specifically recognizes the 95-100 kDa β2 subunit (CD18), which is found on the majority of leukocytes as a heterodimer with any of the three distinct CD11 α integrin subunits (CD11a or αL, CD11b or αM, CD11c or αX) to form, respectively, LFA-1, Mac-1, and gp150, 95. The function-blocking activity of WT.3 antibody has been determined in several in vitro assays measuring the binding of LFA-1 (αLβ2 integrin) to ICAM-1 (CD54). It has also been reported that WT.3 mAb inhibits leukocyte infiltration in an in vivo system.
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.