Proximity Extension Assay
Olink Proteomics has developed a series of protein biomarker panels, which use a unique technology (Proximity Extension Assay) enabling high-throughput, multiplex immunoassay-qPCR that measures 92 proteins across 88 samples simultaneously.
The main steps involved in the protein quantification analysis are outlined in the figure to the left. Each immunoassay targeting a specific protein consists of two antibodies. The antibodies are labeled with one oligo each, which have a region of complementarity to each other. When the two antibodies bind simultaneously to the protein, the oligos will be in such proximity that they will hybridize, and the sequences are extended to form a double-stranded oligonucleotide. The oligonucleotide works as a substrate for a qPCR reaction and is subsequently amplified and quantified by fluorescence intensity using the Fluidigm qPCR system.
The innovative dual recognition, DNA-coupled methodology provides exceptional readout specificity, enabling high multiplex, rapid throughput protein biomarker analysis without compromising on data quality and assay robustness.