Exosomes are small membrane-bound vesicles that in recent years have emerged as important molecules for inter-cellular communication. Exosomes are produced during both normal and patho/physiological conditions, and cancer cells have been shown to secrete exosomes in greater amounts than normal cells. CD81 is a 26 kD non-glycosylated member of the tetraspanin superfamily (TM4SF),which is expressed on T and B cells, NK cells, monocytes, dendritic cells, thymocytes, endothelial cells, and fibroblasts.CD81 associates with several other cell-surface proteins in a multimolecular complex, including CD19, CD21, CD20, CD37, CD53, and CD82 in B cells, and CD4, CD8, and CD82 in T cells. CD81 is frequently expressed on exosome membranes used to characterize exosome populations from a variety of body fluids.

The Exosomal Marker (CD81) Antibody Set Kit provides an economical means to evaluate the presence of exosomal markers. The kit includes enough primary antibody to perform at least 10 western blot experiments for each target. The secondary antibody that is included in this kit has been optimized to enhance the signal-to-noise ratio. We do not recommend using other secondary antibodies with the primary antibodies at this time.