Cat Deoxypyridinoline (DPD) ELISA Kit

This assay employs a two-site sandwich ELISA to quantitate DPD in samples. An antibody specific for DPD has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any DPD present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for DPD is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of DPD bound in the initial step. The color development is stopped and the intensity of the color is measured.

Deoxypyridinoline (Dpd) is one of the two pyridinium cross-links that provide structural rigidity to type I collagen in bone. During osteoclastic resorption, Dpd is released into circulation and is excreted in the urine in free and peptide-bound forms.Deoxypyridinoline (Dpd) occurs mainly in Type I collagen of bone. After the formation of the Type I collagen matrix, the action of lysyl oxidase on two hydroxylysine and a lysine residue result in the formation of a Dpd cross link between two triple helical strands of collagen. Deoxypyridinoline (Dpd) has been described as a marker of bone turnover in metastatic breast cancer.Pyridinoline (PYD) and Deoxypyridinoline (DPD) are the major stable cross-links. These cross-links, primarily in bone and cartilage, have been found in all the connective tissues except the skin. PYD is the major component of these tissues, whereas DPD has only been detected in bone and dentine.

This assay has high sensitivity and excellent specificity for detection of Human DPD. No significant cross-reactivity or interference between Human DPD and analogues was observed.

The linearity of the kit was assayed by testing samples spiked with appropriate concentration of Human DPD and their serial dilutions. The results were demonstrated by the percentage of calculated concentration to the expected.

The stability of ELISA kit is determined by the loss rate of activity. The loss rate of this kit is less than 5% within the expiration date under appropriate storage condition. The loss rate was determined by accelerated thermal degradation test. Keep the kit at 37°C for 4 and 7 days, and compare O.D.values of the kit kept at 37°C with that of at recommended temperature. (referring from China Biological Products Standard, which was calculated by the Arrhenius equation. For ELISA kit, 4 days storage at 37°C can be considered as 6 months at 2 - 8°C, which means 7 days at 37°C equaling 12 months at 2 - 8°C).

Serum: Use a serum separator tube (SST) and allow samples to clot for two hours at room temperature or overnight at 2 - 8°C before centrifugation for 15 minutes at 1000 × g. Remove serum and assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles. Plasma: Collect plasma using EDTA, or heparin as an anticoagulant. Centrifuge for 15 minutes at 1000 × g at 2 - 8°C within 30 minutes of collection. Assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles.

Other biological fluids: Centrifuge samples for 20 minutes at 1000 × g. Remove particulates and assay immediately or store samples in aliquot at -20°C or -80°C. Avoid repeated freeze/thaw cycles.