Description
Apolipoproteins are proteins that bind to lipids to form lipoproteins, whose main function is to transport lipids. Apolipoproteins are key in maintaining the structural integrity and solubility of lipoproteins. ApoE is a fat-binding protein that is part of the chylomicron and Intermediate-Density Lipoprotein (IDLs). It is essential for the normal catabolism of triglyceride-rich lipoprotein constituents. A correlation between ApoE and neurodegenerative conditions such as multiple sclerosis and Alzheimer's disease has been found.
HTRF assays offer many advantages over other technologies:
Homogeneous add-and-read format
No wash steps
Low background
Straightforward miniaturization from 96- or 384-well microplates to high density assay formats such as 384-well low volume and 1536-well plates
Stable signal, providing flexibility in time of readout or size of assays
Assay principle
The Apolipoprotein E assay is a sandwich immunoassay involving two monoclonal antibodies, one labelled with Eu-Cryptate (Donor) and the second with d2 (Acceptor). The intensity of the signal is proportional to the concentration of apolipoprotein present in the sample.
Assay protocol
The ApoE assay features a streamlined protocol with only one incubation step following the sample/calibrator and Antibody conjugates dispensing. The antibodies labelled with HTRF donor and acceptor may be pre-mixed and added in a single dispensing step to further streamline the assay procedure. This protocol requires a single 3-hour incubation period at RT.
Apolipoprotein E standard curve
10 µL of recombinant protein in diluent #5 were dispensed to a low volume white microplate before the addition of 10 µL of the premixed HTRF anti ApoE detection reagents. The HTRF signal was recorded after 2h incubation at room temperature.