The 1-155-2 monoclonal antibody specifically recognizes human immunoglobulin lambda light chains (Igλ). Immunoglobulins are expressed on the surface of B lymphocytes and plasma cells, and they also circulate in the serum. The two light chains in an immunoglobulin are of the same type, either kappa (Igκ) or Igλ. Immunoglobulins bearing Igλ are expressed on a minority of normal B lymphocytes and on neoplastic cells of some leukemias, lymphomas, and plasmacytomas. In serum, the 1-155-2 antibody binds to immunoglobulins bearing Igλ as well as free Igλ. It does not bind to Igκ or immunoglobulin heavy chains.
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.