Cat No.: 31030 Other Names: A-FABP, aP2
Introduction
FABP-4, also termed adipocyte fatty-acid binding protein (A-FABP) or AP2, has been shown to play a key role in obesity and
metabolic syndrome. A-FABP knockout mice are substantially protected from insulin resistance, dyslipidemia, type 2 diabetes and
fatty liver disease, despite of increased adipocity. In clinical studies, increased circulating A-FABP levels are found in obese subjects
and associated with non-alcoholic fatty liver disease, stroke, and carotid atherosclerosis.
Principle of the Assay
This assay is a quantitative sandwich ELISA. The immunoplate is pre-coated with a mouse monoclonal antibody specific for
mouse FABP4. Standards and samples are pipetted into the wells and any mouse FABP4 present is bound by the immobilized
antibody. After washing away any unbound substances, a biotin labelled polyclonal antibody specific for mouse FABP4 is added to
the wells. After wash step to remove any unbound reagents, streptavidin-HRP conjugate is added, after the last wash step, an HRP
substrate solution is added and colour develops in proportion to the amount of mouse FABP4 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 mouse FABP4, 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.
Mouse FABP4 (ng/mL) | Absorbance (450 nm) | Blanked Absorbance |
0 | 0.110 | 0 |
0.39 | 0.168 | 0.058 |
0.78 | 0.227 | 0.118 |
1.56 | 0.365 | 0.255 |
3.12 | 0.615 | 0.505 |
6.25 | 0.922 | 0.812 |
12.5 | 1.451 | 1.341 |
25 | 2.128 | 2.018 |
B. Sensitivity
The lowest level of FABP4 that can be detected by this assay is 0.39 ng/mL.
C. Specificity
The antibodies used in this assay are specific to mouse FABP4 and do not cross-react with other cytokine or hormone
molecules.
D. Precision
Intra-assay Precision (Precision within an assay) C.V. <4.1%.
Inter-assay Precision (Precision between assays) C.V.<4.5%.