Proseek® Multiplex is a generation of multiplexed protein biomarker immunoassays based on the Proximity Extension Assay (PEA) platform. Proseek Multiplex allows biomarker researchers to quantify 92 proteins in one microliter sample against a panel of analytes such as growth factors, inflammatory markers, soluble receptors, and cancer antigens. Reduced sample consumption makes Proseek Multiplex suitable for retroactively mining biobanked serum samples for multivariate biomarker signatures. It can also provide biomarker insights from sample types such as tissue lysates of needle biopsies and microdialysis samples. Proseek Multiplex can provide quantification below picogram per milliliter levels.