Revision 4

#74220Store at -20C

1 Kit

(8 x 20 microliters)

Cell Signaling Technology

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For Research Use Only. Not for Use in Diagnostic Procedures.
Product Includes Product # Quantity Mol. Wt Isotype/Source
Alix (3A9) Mouse mAb 2171 20 µl 95 kDa Mouse IgG1
Annexin V Antibody 8555 20 µl 30 kDa Rabbit 
CD54/ICAM-1 (E3Q9N) XP® Rabbit mAb 67836 20 µl 89, 92 kDa Rabbit IgG
CD9 (D8O1A) Rabbit mAb 13174 20 µl 22, 24, 35 kDa Rabbit IgG
GM130 (D6B1) XP® Rabbit mAb 12480 20 µl 140 kDa Rabbit IgG
EpCAM (D1B3) Rabbit mAb 2626 20 µl 40 kDa Rabbit IgG
HSP70 (D69) Antibody 4876 20 µl 70 kDa Rabbit 
Flotillin-1 (D2V7J) XP® Rabbit mAb 18634 20 µl 49 kDa Rabbit IgG
Anti-rabbit IgG, HRP-linked Antibody 7074 100 µl Goat 
Anti-mouse IgG, HRP-linked Antibody 7076 100 µl Horse 

Please visit for individual component applications, species cross-reactivity, dilutions, protocols, and additional product information.


The Exosomal Marker Antibody Sampler Kit provides an economical means to evaluate the presence of exosomal markers. The kit includes enough primary antibody to perform two western blot experiments for each target.


Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibodies.


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 pathophysiological conditions, and cancer cells have been shown to secrete exosomes in greater amounts than normal cells (reviewed in 1). The exosomal markers contained in this kit are Alix, Annexin V, ICAM-1, CD9, GM130, EpCAM, flotillin, and HSP70.
Alix, a cytosolic scaffold protein, regulates many cellular processes including endocytic membrane trafficking, cell adhesion through interactions with ESCRT (endosomal sorting complex required for transport) proteins, endophilins, and CIN85 (Cbl-Interacting protein of 85 kDa) (2, 3).
Annexin V is a ~30 kDa protein that binds to phospho-lipids in a calcium-dependent manner (4). All annexins contain a putative PKC binding site, but only annexin V has been identified as an inhibitor of this pathway (5).
Intracellular cell adhesion molecule-1 (CD54 or ICAM-1) is a cell surface glycoprotein that belongs to the immunoglobulin superfamily (IgSF) of adhesion molecules. CD54 is expressed at low levels in diverse cell types, and is induced by cytokines (TNF-alpha, interleukin-1) and bacterial lipopolysaccharides (6). Apical localization on endothelial cells (or basolateral localization on epithelial cells) is a prerequisite for leukocyte trafficking through the endothelial (or epithelial) barrier (6).
The CD9 antigen belongs to the tetraspanin family of cell surface glycoproteins. Tetraspanins interact with a variety of cell surface proteins and intracellular signaling molecules in specialized tetraspanin-enriched microdomains (TEMs), where they mediate a range of processes including adhesion, motility, membrane organization, and signal transduction (7). Additional research identified CD9 as an abudant component of exosomes, and may play a role in the fusion of these secreted membrane vesicles with recipient cells (8).
GM130 is required for membrane fusion events that mediate ribbon formation during Golgi assembly (9). The Golgi apparatus functions in the modification, organization, and transport of proteins and membrane targeted to other parts of the cell, such as the plasma membrane, lysosomes, and endosomes. This regulated transport is important for appropriate protein localization, secretion, and signal transduction (reviewed in 10).
Epithelial cell adhesion and activation molecule (EpCAM/CD326) is a transmembrane glycoprotein that mediates calcium-independent, hemophilic adhesions on the basolateral surface of most epithelial cells (11). One of the first tumor-associated antigens discovered, EpCAM has long been a marker of epithelial and tumor tissue. Research studies have shown that EpCAM is highly expressed in cancer cells and can be used as a biomarker for the detectionof tumor-derived exposomes (reviewed in 1, 12, 13).
Flotillins belong to a famiy of lipid raft-associated integral membrane proteins that are ubiquitously expressed and located to lipid rafts on the cell plasma membrane where they support signal transduction and regulate lipid raft motility and localization (14-17). In addition to its colocalization with lipid rafts on the plasma membrane, flotillin-1 also has been found at compartments of the endocytic and autophagosomal pathways, such as recycling/ late endosomes, the Golgi complex, as well as the nucleus (18, 19).
HSP70 is a molecular chaperone expressed constituitively under normal conditions to maintain protein homeostatis and is induced upon environmental stress (20). HSP70 is able to interact with unfolded proteins to prevent irreversible aggregation and catalyze the refolding of their substrates in an ATP and co-chaperone dependent manner (21). An immune response is elicited upon excretion of heat shock proteins from tumor exosomes (reviewed in 1).

  1. Raposo, G. and Stoorvogel, W. (2013) J Cell Biol 200, 373-83.
  2. Katoh, K. et al. (2003) J Biol Chem 278, 39104-13.
  3. Sadoul, R. (2006) Biol Cell 98, 69-77.
  4. Huber, R. et al. (1990) EMBO J 9, 3867-74.
  5. Cardó-Vila, M. et al. (2003) Mol Cell 11, 1151-62.
  6. Hopkins, A.M. et al. (2004) Adv Drug Deliv Rev 56, 763-78.
  7. Hemler, M.E. (2005) Nat Rev Mol Cell Biol 6, 801-11.
  8. Théry, C. et al. (1999) J Cell Biol 147, 599-610.
  9. Puthenveedu, M.A. et al. (2006) Nat Cell Biol 8, 238-48.
  10. Barr, F.A. and Short, B. (2003) Curr Opin Cell Biol 15, 405-13.
  11. Went, P.T. et al. (2004) Hum Pathol 35, 122-8.
  12. Baeuerle, P.A. and Gires, O. (2007) Br J Cancer 96, 417-23.
  13. Armstrong, A. and Eck, S.L. Cancer Biol Ther 2, 320-6.
  14. Langhorst, M.F. et al. (2005) Cell Mol Life Sci 62, 2228-40.
  15. Stuermer, C.A. and Plattner, H. (2005) Biochem Soc Symp , 109-18.
  16. Fernow, I. et al. (2007) Eur J Cell Biol 86, 345-52.
  17. Neumann-Giesen, C. et al. (2007) J Cell Sci 120, 395-406.
  18. Liu, J. et al. (2005) J Biol Chem 280, 16125-34.
  19. Santamaría, A. et al. (2005) Mol Cell Biol 25, 1900-11.
  20. Nollen, E.A. and Morimoto, R.I. (2002) J Cell Sci 115, 2809-16.
  21. Young, J.C. et al. (2003) Trends Biochem Sci 28, 541-7.

Background References

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