DESCRIPTION

SERPINA12 is also named as Serpin A12 and Visceral adipose tissue-derived serine protease inhibitor (Vaspin). Vaspin is an adipokine belonging to the serpin family, thus also named SERPINA12, with targets in kallikrein 7 and 14 that participates in skin desquamation. Vaspin is a compensatory molecule in obesity and insulin resistance. Vaspin is a newly described adipokine with an insulin sensitizing effect and inhibitory impact on food intake.

PRINCIPLE OF THE ASSAY

An anti-tag antibody is pre-coated onto the bottom of wells. After adding antigen or samples, Tagged-Capture antibody and HRP-conjugated detection antibody, a sandwich complex is formed in the solution. TMB acts as a HRP substrate, and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns the solution yellow. The color intensity is proportional to the quantity of bound protein, which is measurable at 450 nm with the correction wavelength set at 630 nm.

PRECISION

Intra-assay Precision (Precision within an assay) Three samples of known concentration were tested 8 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 16 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	8	2,542.9	81.5	3.2
2	8	641.3	7.6	1.2
3	8	331.5	2.9	0.9

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	2,539.8	69.0	2.7
2	16	630.6	14.7	2.3
3	16	324.5	8.6	2.7

RECOVERY

The recovery of human SERPINA12/Vaspin spiked to three different levels throughout the range of the assay was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:8	107	104-110
	1:16	107	102-113
Saliva	1:2	113	110-118

LINEARITY

To assess the linearity of the assay, saliva samples were spiked with high concenthumanions of human SERPINA12/Vaspin and diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. Human plasma samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The human plasma was initially diluted 1:4.)

		Human plasma	Saliva
1:2	Average% of Expected	100	90
	Range (%)	-	88-92
1:4	Average% of Expected	104	79
	Range (%)	101-108	72-86
1:8	Average% of Expected	104	94
	Range (%)	99-109	87-100
1:16	Average% of Expected	111	111
	Range (%)	96-126	110-112

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human SERPINA12/Vaspin One-Step ELISA Kit produced at Sunlong Medical™.