The Quantikine Human KLK3/PSA Immunoassay is a 4.5 hour solid phase immunoassay designed to measure KLK3/PSA in cell culture supernates, serum, and plasma. It contains NS0-expressed recombinant human KLK3/PSA, and antibodies raised against the recombinant protein. Natural human KLK3/PSA showed dose-response curves that were parallel to the standard curves obtained using the recombinant Quantikine kit standards, indicating that this kit can be used to determine relative levels of natural human KLK3/PSA.
Intra-Assay Precision (Precision within an assay) Three samples of known concentration were tested on one plate to assess intra-assay precision.
Inter-Assay Precision (Precision between assays) Three samples of known concentration were tested in separate assays to assess inter-assay precision.
Serum, EDTA Plasma, Heparin Plasma
Cell Culture Supernates
The recovery of KLK3/PSA spiked to levels throughout the range of the assay in various matrices was evaluated.
Average % Recovery
Cell Culture Media (n=4)
EDTA Plasma (n=4)
Heparin Plasma (n=4)
To assess the linearity of the assay, samples containing and/or spiked with high concentrations of KLK3/PSA were serially diluted with the appropriate Calibrator Diluent to produce samples with values within the dynamic range of the assay.
Preparation and Storage
Store the unopened product at 2 - 8 °C. Do not use past expiration date.
Background: Kallikrein 3/PSA
The human tissue kallikrein (KLK) gene family contains 15 members that play important roles in cancer. Notably, kallikrein-1, also known as tissue kallikrein, cleaves kininogen to release the vasoactive kinin peptide, bradykinin or lysyl-bradykinin. Kallikrein-3, called prostate specific antigen (PSA), is an established tumor marker that aids in the diagnosis, staging, and follow up of prostate cancer. Kallikrein-4 is specifically expressed in the prostate and over-expressed in prostate cancer. Kallikrein-5 is widely expressed but found at high levels in skin, breast, brain and testis; over-expression is an indicator of poor prognosis in ovarian cancer. Kallikrein-8 is expressed in the brain and is a novel marker of ovarian and cervical cancer.
Human plasma kallikrein, a serine protease, is synthesized in the liver and circulates in the plasma bound to high molecular weight (HMW) kininogen or as a free zymogen. Once activated by its physiological activator, coagulation factor XII, it displays endopeptidase activity towards peptide bonds after arginine (preferred) and lysine. It cleaves HMW kininogen, its major physiological substrate, to release the potent vasodilator peptide bradykinin. It is also able to cleave a number of inactive precursor proteins to generate active products, such as plasminogen and prourokinase.
Refer to the product for complete assay procedure.
Bring all reagents and samples to room temperature before use. It is recommended that all samples, standards, and controls be assayed in duplicate.
Prepare all reagents, standard dilutions, and samples as directed in the product insert.
Remove excess microplate strips from the plate frame, return them to the foil pouch containing the desiccant pack, and reseal.
100 µL Assay Diluent
Add 100 µL of the appropriate Assay Diluent to each well.
50 µL Standard, Control, or Sample
Add 50 µL of Standard, control, or sample to each well. Cover with a plate sealer, and incubate at room temperature for 2 hours.
Aspirate each well and wash, repeating the process 3 times for a total of 4 washes.
200 µL Conjugate
Add 200 µL of Conjugate to each well. Cover with a new plate sealer, and incubate at room temperature for 2 hours.
Aspirate and wash 4 times.
200 µL Substrate Solution
Add 200 µL Substrate Solution to each well. Incubate at room temperature for 30 minutes. PROTECT FROM LIGHT.
50 µL Stop Solution
Add 50 µL of Stop Solution to each well. Read at 450 nm within 30 minutes. Set wavelength correction to 540 nm or 570 nm.
R&D Systems personnel manually curate a database that contains references using R&D Systems products.
The data collected includes not only links to publications in PubMed,
but also provides information about sample types, species, and experimental conditions.
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