Proximity Extension Assay

**Semantic type:** Laboratory Procedure

**Definition:** A type of multiplex immunoassay that utilizes pairs of oligonucleotide-labeled antibodies to detect and quantify proteins in a sample. In this assay, the antibodies bind to their target proteins, and when in close proximity, the oligonucleotides are extended and amplified through a polymerase reaction. The resulting DNA products are then quantified using real-time PCR, allowing for sensitive and specific measurement of protein levels in complex biological samples.

**Synonyms:** - PEA - PROXIMITY EXTENSION ASSAY