The L303.1 monoclonal antibody specifically recognizes the human CD2 antigen. CD2 is a 45-50 kDa type I transmembrane glycoprotein that also forms the binding site for sheep erythrocytes. The CD2 antigen is present on approximately 75% of normal peripheral blood lymphocytes and 95% to 99% of thymocytes. It is also found on a subset of monocytes (approximately one-third) that might be precursors to dendritic cells. The CD2 antibody reacts with essentially all T lymphocytes and with a subset of NK lymphocytes. CD2 and CD58 have been shown to be coreceptors. The interaction of CD2 antigen and CD58 antigen facilitates antigen recognition by T lymphocytes.
The antibody was conjugated to BD Horizon™ BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.