Description
Enzyme immunoassay for the quantitative determination of Monomeric C-Reactive Protein (mCRP) in human serum and plasma samples. Quality controls are included with the kit. Developed and manufactured in Europe by PromedeusLab.
Summary
C-reactive protein (CRP) is a multipotent protein that undergoes conformational changes between circulating native pentameric CRP (pCRP), pentameric symmetrical forms (pCRP*) and monomeric CRP (mCRP) forms. mCRP exhibits strong pro-inflammatory activity and activates platelets, leukocytes, and endothelial cells. Abundant deposition of mCRP in inflamed tissues plays a role in several disease conditions, such as ischemia/reperfusion injury, Alzheimer’s disease, and cardiovascular disease. Conversion of pCRP to mCRP induces inflammatory signalling, monoacyl phosphatidylcholine generated by PLA2, or by oxidation lipid acyl chains, promotes binding and dissociation of pCRP to mCRP. mCRP gains functionally active neoepitopes that carry out highly pro-inflammatory and prothrombotic features, thus mCRP can bind cholesterol and enter the plasma membrane and activate pro-inflammatory responses. Deposition of mCRP, which has a much lower aqueous solubility than pCRP, has been shown in the brain in infarcted areas of Alzheimer's disease patients and in regions with amyloid burden, in atherosclerotic plaques in vascular disease and in other foci of inflammatory tissue injuries.
Principle of Method
The microtiter plate is coated with the antibody specifically binding the mCRP. Human serum or plasma is incubated on the plate coated with the capture antibody. The sample is washed out of the wells and the specifically bound mCRP protein is incubated with biotin-labelled detection antibody. Following another washing step, Streptavidin-HRP conjugate is added into the well. Unbound reagent is then washed out. Horseradish peroxidase (HRP) bound in the complex reacts with the chromogenic substrate (TMB) creating the blue color. The reaction is stopped by addition of STOP solution (H2SO4).
The absorbance values are measured at 450 nm (optionally 450/630 nm) and are proportional to the concentration of mCRP in the sample. The concentration of mCRP in unknown samples is determined from the calibration curve which is created by plotting the absorbance values against the standard concentration values.
Sample Types
Plasma or serum.
Typical Standard Curve
Assay Range: 1.25 ng/mL - 80 ng/mL
Sensitivity
The limit of detection, defined as a concentration of human MCRP giving absorbance higher than absorbance of blank + 3 standard deviations, is better than 0.63 ng/mL of sample.
Precision
Intra-Assay
| Test sample | Mean (ng/mL) | SD | CV |
| 1 |
2.1 | 0.1 |
4.3% |
| 2 |
2.4 |
0.2 |
8.1% |
Inter-Assay (Run-to-Run)
| Test sample | Mean (ng/mL) | SD | CV |
| 1 |
41.6 |
6.7 |
14.5% |
| 2 |
8.8 |
0.4 |
5% |
Accuracy
Dilution Linearity:
| Test sample | Dilution |
Measured Concentration (ng/mL) |
Expected Concentration (ng/mL) |
Yield |
| 1 |
39.4 |
- | - | |
| 1 | 2x | 18.7 |
196.6 |
95% |
| 1 | 4x | 9.5 |
98.5 | 96% |
| 1 | 8x | 4.7 |
49.2 | 96% |
| 2 |
185.8 |
- |
- | |
| 2 | 2x | 96.5 |
92.9 |
104% |
| 2 | 4x | 46.6 |
46.4 |
100% |
| 2 | 8x | 22.6 |
23.2 |
97% |
Spiking Recovery:
| Test sample | Spike (ng/mL) |
Measured Concentration (ng/mL) |
Expected Concentration (ng/mL) |
Yield |
| 1 |
- | 3.27 |
- | - |
| 1 | 20 |
20.0 |
23.3 |
86% |
| 1 | 10 |
11.6 |
13.3 |
88% |
| 1 | 5 |
7.2 |
8.3 |
87% |
Storage
The kit must be stored at 2–8 °C. The opened components can be stored for one week at 2–8 °C.
Usage
This assay is for in vitro research use only and is not for use in diagnostic procedures.
Population & Clinical Data
Typical mCRP values in human serum were obtained with Promedeus Assays Human Monomeric CRP (mCRP) ELISA kit.
| Population | mCRP level |
| Individuals with hsCRP 1-5 mg/L | 1.2 - 4.8 ng/mL (median 2.6 ng/mL) |
|
Individuals with pancreatic cancer |
18.3 - 73.9 ng/mL (median 36.5 ng/mL) |
|
Indivduals with bacterial infection, CRP > 50 mg/L |
24.1 - 98.3 ng/mL (median 47.7 ng/mL) |
Resources
Summary References
- García-Lara E, Aguirre S, Clotet N, Sawkulycz X, Bartra C, Almenara-Fuentes L, Suñol C, Corpas R, Olah P, Tripon F, Crauciuc A, Slevin M, Sanfeliu C. Antibody Protection against Long-Term Memory Loss Induced by Monomeric C-Reactive Protein in a Mouse Model of Dementia. Biomedicines. 2021 Jul 16;9(7):828. doi: 10.3390/biomedicines9070828. PMID: 34356892; PMCID: PMC8301488.
Ilex Life Sciences LLC is an authorized distributor of PromedeusLab.