< 0.5% cross-reactivity observed with available related molecules.Cross-species reactivity not tested.
No significant interference observed with available related molecules.
The Quantikine Human Endostatin Immunoassay is a 4.5 hour solid-phase ELISA designed to measure human Endostatin in cell culture supernates, serum, plasma, and saliva. It contains E. coli-expressed recombinant human Endostatin and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human Endostatin showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for naturally occurring Endostatin.
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.
The recovery of Endostatin 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 Endostatin were serially diluted with 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.
Endostatin is a 20 kDa proteolytic fragment of the C-terminal, non-collagenous (NC1) domain of type XVIII Collagen. It was originally identified as a factor produced by murine hemangioendothelioma cells that could specifically inhibit endothelial cell proliferation and angiogenesis. Although the molecular signals that trigger the release of Endostatin from type XVIII Collagen are not well understood, multiple proteases have been suggested to be involved in its generation including Cathepsins S, B, L, and V, Elastase, and matrix metalloproteinases (MMPs)-2, -7, and -9. Endostatin is of particular interest as it has been shown to inhibit the growth of many primary and metastatic tumors. It may also be involved in down-regulating angiogenesis during physiological processes such as wound healing and the establishment of placental circulation. The anti-angiogenic activity of Endostatin is attributable to its ability to inhibit endothelial cell proliferation and suppress VEGF-and FGF basic-induced endothelial cell migration and adhesion. Many of these effects are thought to be mediated by interactions between Endostatin and endothelial cell-expressed Transglutaminase 2, Heparin, and Integrins alpha 5 beta 1 and alpha V beta 3.
Entrez Gene IDs
80781 (Human); 12822 (Mouse);
antiangiogenic agent; COL18A1; collagen alpha-1(XVIII) chain; collagen, type XVIII, alpha 1; FLJ27325; FLJ34914; human type XVIII collagen10endostatin; KNO; KNO1MGC74745; Knobloch syndrome, type 1; KS; multi-functional protein MFP;
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 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 on a horizontal orbital microplate shaker.
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 on the shaker.
Aspirate and wash 4 times.
200 µL Substrate Solution
Add 200 µL Substrate Solution to each well. Incubate at room temperature for 30 minutes on the benchtop. 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.
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