Syndecan-1, designated CD138, is a dimeric type I transmembrane (TM) protein that belongs to the syndecan family of Type 1 transmembrane proteins . The four syndecan family members are major carriers of heparan sulfate (HS) and chondroitin sulfate glycosaminoglycans (GAGs) that have different expression patterns and extracellular sequences. Syndecan-1 forms weak non-covalent homodimers, or heterodimers with Syndecan-2 or -3, through interactions of the transmembrane domain. It is synthesized as a 310 amino acid (aa) precursor with a 17 aa signal sequence, a 234 aa extracellular domain (ECD) that includes three closely-spaced consensus Ser-Gly HS attachment sites near the N-terminus, a 25 aa TM segment, and a 34 aa cytoplasmic region that includes a PDZ binding motif with a tyrosine phosphorylation site. The ECD is variably modified by GAGs, producing molecular weights of 120 - 200 kDa for native Syndecan-1. Soluble forms are shed via proteolytic cleavage. Human Syndecan-1 ECD shares 65 - 71% aa identity with the ECD of rat, mouse, canine, equine and bovine Syndecan-1. Syndecan-1 shows highest expression on epithelial cells such as keratinocytes, and terminally differentiated B cells such as plasma cells. It aids wound healing in skin, cornea, and heart following myocardial infarction by promoting re-epithelialization, migration, and collagen deposition. It binds chemokines, creating chemotactic gradients when shed, but also binds and modulates integrins to control the influx of leukocytes. The net effect is to allow, but limit, inflammation. In myeloma and other cancers, shedding of Syndecan-1 can facilitate growth, angiogenesis and metastasis. Growth factors, such as FGFs and HGF, bind GAG chains and use Syndecan-1 as a coreceptor. The GAG chains may also be used by a variety of viruses and bacteria for cell adhesion and uptake.

This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for Syndecan-1 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any Syndecan-1 present is bound by the immobilized antibody. Following incubation unbound samples are removed during a wash step, and then a detection antibody specific for Syndecan-1 is added to the wells and binds to the combination of capture antibody-Syndecan-1 in sample. Following a wash to remove any unbound combination, and enzyme conjugate is added to the wells. Following incubation and wash steps a substrate is added. A coloured product is formed in proportion to the amount of Syndecan-1 present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven Syndecan-1 standard dilutions and Syndecan-1 sample concentration determined.

Figure 1:Schematic diagram of the assay

1. Aluminium pouches with a Microwell Plate coated with antibody to Human Syndecan-1 (8 x 12)

2. 2 vials Human Syndecan-1 Standard lyophilized, 8000 pg/ml upon reconstitution

3. 2 vials concentrated Biotin-Conjugate anti-Human Syndecan-1 antibody

4. 2 vials Streptavidin-HRP solution

5. 1 bottle Standard /sample Diluent

6. 1 bottle Biotin-Conjugate antibody Diluent

7. 1 bottle Streptavidin-HRP Diluent

8. 1 bottle Wash Buffer Concentrate 20x (PBS with 1% Tween-20)

9. 1 vial Substrate Solution

10. 1 vial Stop Solution

11. 4 pieces Adhesive Films

12. package insert

NOTE: [96 Tests]

Unopened Kit：Store at 2 -8° C. Do not use past kit expiration date. opened/ReconstitutedReagents：Please refer to the datasheets for detail information.

1. Circulating syndecan-1 is associated with chemotherapy-resistance in castration-resistant prostate cancer. Szarvas T, et al. Urol Oncol, 2018 Jun.

2. Syndecan-1 suppresses epithelial-mesenchymal transition and migration in human oral cancer cells. Wang X, et al. Oncol Rep, 2018 Apr.

3. Molecular targets and signaling pathways regulated by nuclear translocation of syndecan-1. Szatmári T, et al. BMC Cell Biol, 2017 Dec 8.

4. Circulating syndecan-1 predicts the development of disseminated intravascular coagulation in patients with sepsis. Ikeda M, et al. J Crit Care, 2018 Feb.

5. Syndecan-1: A Quantitative Marker for the Endotheliopathy of Trauma.

Gonzalez Rodriguez E, et al. J Am Coll Surg, 2017 Sep.