DESCRIPTION

ANGPTL3 is a secreted glycoprotein primarily synthesized by hepatocytes and belongs to the angiopoietin-like protein family. ANGPTL3 plays a critical role in both biological processes, such as lipid metabolism, angiogenesis, and hematopoietic function, and pathological changes, including atherosclerosis, carcinogenesis, nephrotic syndrome, diabetes, liver diseases and so on. ANGPTL3 inhibits low-density lipoprotein (LDL) and endothelial lipase (EL), two enzymes that hydrolyze triglycerides and phospholipids in plasma lipoproteins. ANGPTL3-deficient mice showed low plasma HDL cholesterol and HDL phospholipid (PL). ANGPTL3 can also regulate triglyceride metabolism by inhibiting lipoprotein lipase (LPL). ANGPTL3-deficient mice exhibit hypotriglyceridemia and elevated LPL activity.

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	429.5	10.8	2.5
2	8	115.0	8.5	7.4
3	8	61.8	3.5	5.7

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	443.0	31.0	7.0
2	16	114.0	6.3	5.5
3	16	60.4	3.1	5.1

RECOVERY

The recovery of mouse Angiopoietin-like 3/ANGPTL3 spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Mouse serum	1:8,000	90	87-92
	1:16,000	88	87-91
Cell culture supernatant	1:8	85	77-91
	1:16	87	84-91

LINEARITY

To assess the linearity of the assay, samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The mouse serum was initially diluted 1:1,000. The cell culture supernatant was initially diluted 1:2.)

		Mouse serum	Cell culture supernatant
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	90	115
	Range (%)	89-91	111-118
1:8	Average% of Expected	85	103
	Range (%)	83-86	99-107
1:16	Average% of Expected	83	108
	Range (%)	77-90	106-110

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Mouse Angiopoietin-like 3/ANGPTL3 One-Step ELISA Kit produced at Sunlong Medical™.