Abstract: Improved apparatus, compositions, and methods for carrying out interferometry-based assays for detecting analytes in a sample through the use of a precipitating substrate to enhance an interferometry binding signal, and kits useful for carrying out these assays. Methods comprise providing an optical assembly comprising an optical element with a transparent material and adapted for coupling to a light source via a fiber, a first reflective surface and a second reflecting surface having a first analyte-binding molecule and separated from said first surface by a distance, d, exposing said optical element to a sample comprising said analyte, a second analyte binding molecule, and a precipitating substrate; and detecting a change in thickness at said first reflective surface thereby detecting said analyte in said sample. Kits include reagents for derivatizing assay components along with packaging and instructions for use.

Abstract: Disclosed are enzyme assays using biolayer interferometry. Assays may be carried out using immobilized substrate or with a substrate capture format. In certain embodiments, the assays are carried out using unlabeled substrates. The methods are broadly applicable to enzyme assay measurements, can be carried out in vivo or in vitro, and are easily multiplexed.

Abstract: Disclosed are enzyme assays using biolayer interferometry. Assays may be carried out using immobilized substrate or with a substrate capture format. In certain embodiments, the assays are carried out using unlabeled substrates. The methods are broadly applicable to enzyme assay measurements, can be carried out in vivo or in vitro, and are easily multiplexed.

Abstract: Disclosed are enzyme assays using biolayer interferometry. Assays may be carried out using immobilized substrate or with a substrate capture format. In certain embodiments, the assays are carried out using unlabeled substrates. The methods are broadly applicable to enzyme assay measurements, can be carried out in vivo or in vitro, and are easily multiplexed.