PHASIQ’s Micropatterned Phase-Separation Technology (MPS™) eliminates false signals in multiplex enzyme-linked immunosorbent assay (ELISA). Traditional multiplex ELISA suffers from cross-reactions when antibodies are applied in a bath or cocktail. In the figure below, red dotted outlines surround mismatched antibody-protein-antibody sandwiches.
Our proprietary microdroplets confine complementary detection and capture antibodies. They separate antibodies that might cross-react. This confinement eliminates the false positives and false negatives caused by cross-reactivity.
How it Works
Specifically, we create aqueous two-phase systems (ATPSs) on the assay plates to segregate the antibody pairs. Our ATPS use two phase-separation-promoting polymers: polyethylene glycol (PEG) and dextran (DEX). These polymers keep detection antibodies localized only above corresponding capture antibodies.
Our patented assay is conducted in a PEG solution. We spot droplets of DEX on the bottom of the plate where they form a dome during the assay due to interfacial tensions between DEX-PEG and DEX-assay plate. In the figure above, the orange boundary outlines the DEX microdroplet. Partitioning effects keep the detection antibodies in the DEX domes. More information on this method can be found in Eiden et al. 2016 .
We ship pre-spotted assay plates to our customers, who add their test samples, supplied standards, and protocol reagents to the plates. Our plates can be read by any chemiluminescence reader, such as a Western blot reader. Our protocol is familiar to anyone who has used ELISA, offering economies of scale through multiplexing and greater accuracy than other multiplex options.
Our phase-separated droplets prevent antibody cross-talk. Because of this capability PHASIQ assays can return clean data for protein combinations others cannot, conserving time and precious research samples.
Eiden, L.; Yamanishi, C.; Takayama, S.; Dishinger, JF. “Aqueous two-phase system rehydration of antibody-polymer microarrays enables convenient compartmentalized multiplex immunoassays” Anal Chem 2016 DOI: 10.1021/acs.analchem.6b02960.