-
Assay Length
4.5 hours
-
Specificity
Natural and recombinant human M-CSF
-
Cross-reactivity
< 0.5% cross-reactivity observed with available related molecules.< 50% cross-species reactivity observed with species tested.
-
Interference
No significant interference observed with available related molecules.
Control Available
QC21, Quantikine Immunoassay Control Group 4 -
Product Summary
The Quantikine Human M-CSF Immunoassay is a 4.5 hour solid phase ELISA designed to measure human M-CSF in cell culture supernates, serum, plasma, saliva, and urine. It contains CHO cell-expressed recombinant human M-CSF and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human M-CSF 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 human M-CSF.
Precision
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.
Cell Culture Supernates, Saliva, Urine | Intra-Assay Precision | Inter-Assay Precision |
Sample | 1 | 2 | 3 | 1 | 2 | 3 |
n | 20 | 20 | 20 | 40 | 40 | 40 |
Mean | 248 | 751 | 1503 | 280 | 827 | 1620 |
Standard Deviation | 19.4 | 16.1 | 49 | 30.2 | 76 | 87.7 |
CV% | 7.8 | 2.1 | 3.3 | 10.7 | 9.2 | 5.4 |
Serum, EDTA Plasma, Heparin Plasma | Intra-Assay Precision | Inter-Assay Precision |
Sample | 1 | 2 | 3 | 1 | 2 | 3 |
n | 20 | 20 | 20 | 40 | 40 | 40 |
Mean | 357 | 951 | 1767 | 343 | 1019 | 1956 |
Standard Deviation | 17.4 | 24.9 | 49.4 | 43.4 | 84.1 | 88.8 |
CV% | 4.9 | 2.6 | 2.8 | 12.6 | 8.3 | 4.5 |
Recovery
The recovery of M-CSF spiked to levels throughout the range of the assay in various matrices was evaluated.
Sample Type | Average % Recovery | Range % |
Cell Culture Media (n=4) | 99 | 90-107 |
EDTA Plasma (n=4) | 100 | 93-106 |
Heparin Plasma (n=4) | 99 | 93-106 |
Serum (n=4) | 101 | 96-106 |
Linearity
To assess the linearity of the assay, samples containing and/or spiked with high concentrations of M-CSF were serially diluted with the appropriate Calibrator Diluent to produce samples with values within the dynamic range of the assay.
Preparation and Storage
Background: M-CSF
M-CSF, also known as CSF-1, is a four-alpha-helical-bundle cytokine that is the primary regulator of macrophage survival, proliferation and differentiation. M-CSF is also essential for the survival and proliferation of osteoclast progenitors. M-CSF also primes and enhances macrophage killing of tumor cells and microorganisms, regulates the release of cytokines and other inflammatory modulators from macrophages, and stimulates pinocytosis. M-CSF increases during pregnancy to support implantation and growth of the decidua and placenta. Sources of M-CSF include fibroblasts, activated macrophages, endometrial secretory epithelium, bone marrow stromal cells and activated endothelial cells. The M-CSF receptor ( c-fms) transduces its pleotropic effects and mediates its endocytosis. M-CSF mRNAs of various sizes occur. Full length human M-CSF transcripts encode a 522 amino acid (aa) type I transmembrane (TM) protein with a 464 aa extracellular region, a 21 aa TM domain, and a 37 aa cytoplasmic tail that forms a 140 kDa covalent dimer. Differential processing produces two proteolytically cleaved, secreted dimers. One is an N- and O- glycosylated 86 kDa dimer, while the other is modified by both glycosylation and chondroitin-sulfate proteoglycan (PG) to generate a 200 kDa subunit. Although PG-modified M-CSF can circulate, it may be immobilized by attachment to type V collagen. Shorter transcripts encode M-CSF that lack cleavage and PG sites and produce an N-glycosylated 68 kDa TM dimer and a slowly produced 44 kDa secreted dimer. Although forms may vary in activity and half-life, all contain the N-terminal 150 aa portion that is necessary and sufficient for interaction with the M-CSF receptor. The first 223 aa of mature human M-CSF shares 88%, 86%, 81% and 74% aa identity with corresponding regions of dog, cow, mouse and rat M-CSF, respectively. Human M-CSF is active in the mouse, but mouse M-CSF is reported to be species-specific.