The 1G8 monoclonal antibody specifically recognizes Endothelial cell-selective adhesion molecule (ESAM). ESAM is a ~55 kDa single-pass type I transmembrane glycoprotein that is encoded by ESAM (Endothelial cell-specific adhesion molecule) which belongs to the immunoglobulin supergene superfamily (IgSF). ESAM contains an IgV-type and IgC2-type domain in its extracellular region followed by a transmembrane sequence and cytoplasmic tail. ESAM is strongly expressed on platelets, megakaryocytes, and endothelial cells at interendothelial cell junctions as well as dendritic cells. Through homophilic interactions, this interendothelial cell adhesion molecule may play roles in regulating vascular permeability and in the extravasation of leucocytes, eg, neutrophils, through blood vessel walls. ESAM is also reportedly expressed on hematopoietic stem cells (HSCs). ESAM-positive cell populations are enriched for multipotent myeloid erythroid progenitors and primitive progenitors with lymphopoietic activity.
The antibody was conjugated to BD Horizon™ BV786 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 786-nm. BD Horizon BV786 can be excited by the violet laser and detected in a filter used to detect Cy™7-like dyes (eg, 780/60-nm filter).