Sample Plates for Low-Volume High-Throughput Screening

1 Sample Plates for Low-Volume High-Throughput Screening 

To ensure the integrity and stability of compounds used in HTS assays and to maximize the number of HTS screens, which can be performed with microgram quantities of compounds, all research sites at Roche use prealiquoted compound samples that are delivered to the HTS labs in sealed, ready-to-use sample plates . The sample plates contain aliquots of frozen millimolar compound solutions in water-free DMSO, 1 aL per well, corresponding to a small liquid droplet of approximately 1 mm diameter. The sample plate is a standardized, low-cost 384-well plate made from polypropylene with a tapered or parabolic well bottom forming a cavity for the small aliquot. This sample distribution concept for the HTS compound library is based on the following rationale  

The aliquoted compound samples for one full library screen of 1 million compounds fit into the wells of 2841, 384-well plates (352 compounds per plate), or into 

2 High-Density Assay Plates for HTS and Multidimensional Compound Profiling 

Colorimetric assays use the optical density (OD) of the solution in the well or the change of the OD as a function of time as the readout parameter. These assays are typically applied to quantify the activity of enzymes by measuring the color change in the well originating from the differences in absorbance spectra between educt and 

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