The 512 monoclonal antibody specifically recognizes a 65-kDa and 55-kDa molecules of the erythrocyte membrane, which are the rat counterpart of mouse Crry/p65, a membrane inhibitor of complement component C3 convertase. Crry/p65 is widely distributed, predominantly expressed on endothelial cells and all circulating cells. This molecule was also detected on immature hepatocytes, systemic endothelial cells, skin fibroblasts, bronchial epithelial cells, bile canaliculi, the Schwann sheath of peripheral nerve fibers, and ependymal cells. Mouse Crry/p65 uses the same mechanisms as human Decay-Accelerating Factor (DAF) and human Membrane Cofactor Protein (MCP) in inhibiting C3 and C5 convertases, but it is not homologous to either DAF or MCP. It has been proposed that Crry/p65 is the mouse genetic homologue of human CR1 (CD35).
The antibody was conjugated to BD Horizon™ BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max at 421-nm, BD Horizon BV421 can be excited by the violet laser and detected in the standard Pacific Blue™ filter set (eg, 450/50-nm filter). BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific Blue conjugates.