Miniaturized FRET assays and microfluidics: key components for ultra-high-throughput screening.

Assay miniaturization applicable across a wide range of target classes, along with automation and process integration, are well-recognized goals for ultra-high-throughput screening on an industrial scale. This report summarizes the implementation of fluorescence resonance energy transfer (FRET)-based biochemical and cell-based assays in 3456-well NanoWelltrade mark assay plates using key components of Aurora's ultra-high-throughput screening system.

Novel nonsecosteroidal vitamin D mimics exert VDR-modulating activities with less calcium mobilization than 1,25-dihydroxyvitamin D3.

Background: The secosteroid 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) acts through the vitamin D receptor (VDR) to elicit many activities that make it a promising drug candidate for the treatment of a number of diseases, including cancer and psoriasis. Clinical use of 1,25(OH)2D3 has been limited by hypercalcemia elicited by pharmacologically effective doses. We hypothesized that structurally distinct, nonsecosteroidal mimics of 1,25(OH)2D3 might have different activity profiles from vitamin D analogs, and set out to discover such compounds by screening small-molecule libraries.

Quantitation of transcription and clonal selection of single living cells with beta-lactamase as reporter.

Gene expression was visualized in single living mammalian cells with beta-lactamase as a reporter that hydrolyzes a substrate loaded intracellularly as a membrane-permeant ester. Each enzyme molecule changed the fluorescence of many substrate molecules from green to blue by disrupting resonance energy transfer. This wavelength shift was detectable by eye or color film in individual cells containing less than 100 beta-lactamase molecules.