Proximity Extension Assay (PEA) technology is the unique technology behind our Olink^® Explore platform and  Olink^® Target 96 and Target 48 panels. It enables high-throughput, multiplex immunoassays of proteins using minimal volumes of serum, plasma, or almost any other type of biological sample. Here we will show you how our technology delivers this scale of multiplexing and sample throughput without compromising on data quality or assay robustness.

Overcoming the specificity issues of multiplexed immunoassays

Each of the 96 oligonucleotide antibody-pairs contains unique DNA sequences allowing hybridization only to each other. Subsequent proximity extension will create 96 unique DNA reporter sequences which are amplified by real-time PCR. A limiting factor of multiplexed immunoassays is the antibody cross-reactivity which restricts the degree of multiplexing of most assays to below 10-plex. Cross-reactive events will not be detected with Olink’s panels since only matched DNA reporter pairs can hybridize to produce an amplicon for NGS or real-time qPCR. This allows for scalable multiplexing without loss of specificity and sensitivity (see figures below).

A) Conventional immunoassays: cross-reactivity due to unspecific binding of antibodies limits the degree of multiplexing.

B) Olink’s technology: unique DNA oligo sequences report only matched DNA-pairs (e.g. 1A+1B). Cross-reactive events are not detected.