Abstract
The 1536-well microplate format has widely supplanted the 384-well microplate format for high-throughput screening and for IC50 assays. Previously, liquid chromatography/mass spectrometry (LC/MS) analyses of such samples required manual transfers of the wells of interest from a 1536-well plate into a 384-well plate. Because this manual transfer introduced a source of potential error, it became clear that amore appropriate solutionwould be to sample directly from the 1536-well plates. Currently, commercially available 1536-well plate autosamplers are not compatible with Waters LC/MS systems. The authors have modified their CTC PAL autosampler to support injection from up to twenty-four 1536-well plates. This allows them to cherry-pick any sample from up to 36,864 wells on the autosampler. Because of its success at this Institute, sampling from 1536-well plates has not only become the preferredmethod for LC/MS analysis from IC50 plates but also become the standard format used for the handling of and the sampling from large combinatorial libraries.