Insulin is a peptide hormone exclusively produced in pancreatic beta-cells. It consists of A chain and B chain, which are linked by two disulfide bridges.
Insulin is the primary hormone responsible for glucose metabolism. Impaired insulin secretion and insulin resistance are key causes of type 2 diabetes (T2D).

This assay is a two-site ELISA. The micro-plate is pre-coated with a monoclonal antibody against insulin. Standards and samples are added into the wells and coincubated with a monoclonal antibody conjugated to horseradish peroxidase (HRP) enzyme. After wash step to remove any unbound substances, TMB substrate is added and colour develops in proportion to the amount of insulin bound initially. The assay is stopped and the optical density of the wells determined using a micro-plate reader. Since the increases in absorbance are directly proportional to the amount of captured insulin, 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 assay.

Insulin (ng/mL)	Absorbance (450 nm)	Blanked Absorbance
0	0.052	0
0.2	0.063	0.011
0.5	0.098	0.046
1.0	0.197	0.145
2.0	0.558	0.506
3.5	1.23	1.178
7	2.731	2.679

 

B. Sensitivity

The lowest insulin level that can be measured by this assay is 0.2 ng/mL.

 

C. Precision

Intra-assay Precision (Precision within an assay) C.V <6.1%.

Inter-assay Precision (Precision between assays) C.V <2.9%.

 

D. Recovery

The recovery of the assay was determined by adding various amounts insulin to a sample. The measured concentration of the spiked sample in the assay was compared to the expected concentration. The average recovery was 91%.

 

E. Specificity

Percent of cross reactivity

Human insulin: 100%

Rat insulin: 100%

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Insulin ELISA Kit	Assay Range (ng/mL)	Sample Volume Required Per Well (uL)	Assay Length (h)
Ultra sensitive (Rat Cat.: 33380/Mouse Cat.: 32380)	0.025-1.5	25	2.5
High sensitive (Rat Cat.:33270/Mouse Cat.:32270)	0.2-7	10	2
High sensitive Plus(Mouse only Cat.: 32393)	0.2-7	5	2.5
Wide range (Rat Cat.: 33100/Mouse Cat.:32100)	1-50	5	2