The 11F2 monoclonal antibody specifically reacts with a framework epitope of the γ/δ TCR. The γ/δ TCR is a heterodimeric glycoprotein that is noncovalently associated with the CD3 antigen complex. The γ and δ TCR chains are composed of constant and variable regions, each encoded by distinct gene segments. The γ chain forms either disulfide-linked or non-disulfide-linked heterodimers with the δ-subunit. TCR γ/δ is present on a minor subset of T lymphocytes in peripheral blood, thymus, spleen, and lymph node. TCR γ/δ-positive T lymphocytes comprise 1% to 9% of normal peripheral blood lymphocytes and less than 2% of normal thymocytes. The 11F2 antibody is mitogenic for γ/δ-TCR-bearing T lymphocytes.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.