PAR3 ELISA Kit (Protease Activated Receptor 3)

Full Name: PAR3 ELISA Kit (Protease Activated Receptor 3)
Reactivity: Human
Sample Type: Plasma, Tissue Homogenates, Serum, Biological Fluids
Sensitivity: 0.188 ng/ml


PAR3, also known as Protease Activated Receptor 3 is a protein that acts as a receptor, for thrombin and plays a role in signaling processes. It belongs to the family of G protein coupled receptors called protease activated receptors, which have functions in processes like blood clotting, embryonic development and more.

Specifically, PAR3 works together with PAR4 to activate platelets during the formation of blood clots. When a blood vessel is damaged thrombin cleaves the N terminus of PAR3. This causes a change in the shape of the receptor initiating transmembrane signaling through G proteins. This leads to platelet activation and aggregation at the site of injury. While thrombin also activates PAR4, PAR3 reduces the amount of thrombin needed for PAR4 activation. Therefore, PAR3 enhances thrombin signaling through PAR4. This coordinated signaling between PAR3 and PAR4 is critical for directing and optimizing platelet activation at the wound site.

Aside from its role in platelets PAR3 is found in tissues such as endothelium (blood vessel lining) smooth muscle cells, lungs, and brain. Although its functions are less well defined in these contexts it appears that PAR3 contributes to processes, like permeability regulation, vasodilation (widening of blood vessels) and pain signaling by interacting with thrombin molecules, proteases (enzymes that break down proteins) and other members of the protease activated receptor family.

For instance, there is evidence suggesting that PAR3 might play a role, in processes septic conditions and the spread of cancer.


Human PAR3 ELISA kit can measure concentrations of protease activated receptor 3 (PAR3, thrombin, coagulation factor II, PT, serine protease, thrombin-receptor-like) present is plasma, serum, biological fluids or tissue homogenate samples.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • One 96-Well Plate: Pre-coated with anti-PAR3 antibody.
  • Standards: Lyophilized recombinant.
  • Sample/Standard Dilution Buffer.
  • Biotinylated-labelled Antibody.
  • Antibody Dilution Buffer.
  • HRP-Streptavidin Conjugate (SABC).
  • SABC Dilution Buffer.
  • TMB Substrate.
  • Wash Buffer (25x).
  • Plate Sealer.
  • Product Instructions.


For this PAR3 ELISA kit, it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 0.312, 0.625, 1.25, 5, 10, 20 ng/ml.
Reactivity: Human
Sensitivity: 0.188 ng/ml
Range: 0.313 – 20 ng/ml
Principle: Sandwich, Double Antibody
Application: Research Use Only.


– Specificity: Highly specific for PAR3, no cross reactivity or interference between PAR3 and analogues was detected.
– Recovery: Serum (86 – 98%), EDTA Plasma (85 – 104%), Heparin Plasma (87 – 102%).
– Linearity: Serum (85 – 99%), EDTA Plasma (91 – 97%), Heparin Plasma (80 – 95%).
– Precison Intra-Assay: CV < 8%
– Precison Inter-Assay: CV < 10%


  1. Protease Activated Receptors and Arthritis. Int J Mol Sci. (2021) 22 (17): 9352. Lucena F. and McDougall J.J.
  2. Dual Function of Par3 in Tumorigenesis. Front Oncol. (2022) 12: 915957. Lv T., et al.
  3. Thrombin stimulates insulin secretion via protease-activated receptor-3. Islets. (2015) 7 (4): e1118195. Hänzelmann S., et al.
  4. Par3 promotes breast cancer invasion and migration through pull tension and protein nanoparticle-induced osmotic pressure. Biomed Pharmacother. (2022) 155: 113739. Hu Y., et al.


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