Cat No.: 31780 ★Download Datasheet★ ★MSDS★
Introduction
C-peptide is a 31 amino acid peptide which is a part of proinsulin and is cleaved out proteolytically during the formation of insulin.
The half-life of C-peptide is longer (20-30 min) than that of insulin (3-5 min), so C-peptide is a more stable parameter while
assessing b-cell function1.
Principle of the Assay
This assay is a quantitative sandwich ELISA. The immunoplate is pre-coated with a monoclonal antibody specific for human
C-peptide. Standards and samples are pipetted into the wells and any human C-peptide present is bound by the immobilized
antibody. After washing away any unbound substances, a biotin labelled monoclonal antibody specific for human C-peptide is added to the wells. After wash step to remove any unbound reagents, streptavidin-HRP conjugate (STP-HRP) is added. After the last wash step, an HRP substrate solution is added and colour develops in proportion to the amount of human C-peptide bound initially. The
assay is stopped and the optical density of the wells determined using a microplate reader. Since the increases in absorbance are
directly proportional to the amount of captured human C-peptide, the unknown sample concentration can be interpolated from a
reference curve included in each assay.
Assay Performance
A. Typical representation of standard curve
The following standard curve is provided for demonstration only. A standard curve should be generated for each set of sample
assay.
Human C-peptide (pg/mL) | Absorbance (450 nm) | Blanked Absorbance |
0 | 0.063 | 0 |
15.6 | 0.117 | 0.054 |
31.2 | 0.182 | 0.119 |
62.5 | 0.298 | 0.235 |
125 | 0.52 | 0.457 |
250 | 0.934 | 0.871 |
500 | 1.576 | 1.513 |
1000 | 2.533 | 2.47 |
B. Sensitivity
The lowest level of C-peptide hat can be measured by this assay is 15.6 pg/mL.
C. Precision
Intra-assay Precision (Precision within an assay) C.V.<10%.
Inter-assay Precision (Precision between assays) C.V.<10%.