Human Apolipoprotein A-I Quantikine ELISA Kit

Product Summary

The Quantikine Human Apolipoprotein A-I/ApoA1 Immunoassay is a 3.5 hour solid-phase ELISA designed to measure human ApoA1 in cell culture supernates, serum, plasma, and urine. It contains E. coli-expressed recombinant human ApoA1 and has been shown to accurately quantitate the recombinant factor. Results obtained using natural human ApoA1 showed linear curves that were parallel to the standard curves obtained using the Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for naturally occurring human ApoA1.

Preparation and Storage

Background: Apolipoprotein A-I/ApoA1

The apolipoproteins are a structurally-unrelated group of proteins that have some association with the transport of lipids in blood. Apolipoproteins, plus phospholipids, cholesterol and triglycerides, form spherical particles with a lipid/hydrophobic center and a (apolipo)protein coat. The apolipoprotein coat promotes aqueous solubility and serves as a ligand for lipoprotein receptors. HDL may contain apolipoproteins A, C, D, E, J, L and M, while LDL contains apolipoproteins B and E.

ApoAI and ApoA2 are major protein components of serum high-density lipoprotein (HDL) and are produced by the liver and small intestine. They are involved in reverse cholesterol transport from tissues to the liver. Polymorphisms of ApoA2 are associated with disorders of cholesterol and fatty acid metabolism. Human ApoB (Apolipoprotein B-100) is a 550 kDa, secreted, palmitoylated glycoprotein that is part of LDL and VLDL particles. It is made by liver and is 4536 aa in length. It binds LDL to the ApoB/E receptor. ApoC activates lipoprotein lipase and may self-associate to form amyloid-type fibrils.

ApoE is a 34 kDa protein component of serum chylomicrons, VLDL, and HDL particles. It mediates the binding, uptake, and catabolism of these particles through interactions with the ApoE receptor and LDL receptors in the liver and brain. ApoE is important in fatty acid homeostasis and memory formation. Polymorphisms encode three variants (ApoE2, 3, 4) which are differentially related to the development of atherosclerosis and neurogenerative disorders, particularly Alzheimer's disease.

Serum amyloid A proteins (SAAs) are a family of homologous apolipoproteins of high density lipoprotein (HDL). They can be divided into two groups. The first group consists of the acute phase SAA1 and SAA2 that associate with HDL during inflammation and remodel the HDL particle by displacing apolipoprotein A1. The second group consists of constitutively expressed SAA4 and SAA5 that exist as minor apolipoproteins on HDL but make up more than 90% of the total SAA during homeostasis.

Assay Procedure

Refer to the product datasheet for the complete assay procedure.

Bring all reagents and samples to room temperature before use. It is recommended that all samples, standards, and controls be assayed in duplicate.

1、Prepare all reagents, standard dilutions, and samples as directed in the product insert.

2、Remove excess microplate strips from the plate frame, return them to the foil pouch containing the desiccant pack, and reseal.

3、Add 50 μL of Assay Diluent to each well.

4、Add 50 μL of Standard, control, or sample to each well. Cover with a plate sealer, and incubate at room temperature for 2 hours.

5、Aspirate each well and wash, repeating the process 4 times for a total of 5 washes.

6、Add 100 μL of Conjugate to each well. Cover with a new plate sealer, and incubate at room temperature for 2 hours.

7、Aspirate and wash 5 times.

8、Add 100 μL Substrate Solution to each well.

9、Add 100 μL of Stop Solution to each well. Read at 450 nm within 30 minutes. Set wavelength correction to 540 nm or 570 nm.