Lipocalin-2, also known as neutrophil gelatinase-associated lipocalin (NGAL), 24p3, siderocalin, or neutrophil lipocalin (NL), is a secretory glycoprotein expressed in liver, lung, kidney, adipocytes, activated neutrophils and macrophages.
Lipocalin-2 is upregulated under various inflammation and infection conditions and can be served as a sensitive biomarker for various renal injuries. Serum levels of lipocalin-2 are positively correlated with obesity, insulin resistance, hyperglycemia, coronary heart disease and fatty liver disease in humans.

This assay is a quantitative sandwich ELISA using monoclonal antibodies against human LCN2. The immunoplate is pre-coated with a monoclonal antibody specific for human LCN2. Standards and samples are added into the wells and any human LCN2 present is captured by the immobilized antibody. After washing away any unbound substances, a horseradish peroxidase (HRP)-linked monoclonal antibody specific for human LCN2 is added to the wells. After a final washing step to remove any unbound reagents, a HRP substrate solution is added and colour develops in proportion to the amount of human LCN2 bound initially. The reaction 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 LCN2, the unknown sample concentration can be interpolated from a reference curve included in each assay.

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 lipocalin-2 (ng/mL)	Absorbance (450 nm)	Blanked Absorbance
0	0.076	0
0.39	0.107	0.031
0.78	0.137	0.061
1.56	0.203	0.127
3.12	0.343	0.267
6.25	0.647	0.571
12.5	1.26	1.184
25	2.492	2.416

 

B. Sensitivity

The lowest level of lipocalin-2 that can be detected by this assay is 0.39 ng/mL.

 

C. Specificity

The antibody pair used in this assay is specific to human lipocalin-2 and does not cross-react with mouse and rat lipocalin-2, and other cytokine or hormone molecules.

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