Development of silicon microstructures and thin-film MALDI target plates for automated proteomics sample identifications

Here we report on the development of a proteomic platform utilizing a piezo electric flow-through dispensing unit made from silicon microstructures. Th e use of a novel surface coating, where matrix-assisted laser desorption/io nisation time-of-flight mass spectrometry (MALDI MS) targets were uniformly precoated with a thin film of matrix/nitrocellulose, made the sample prepa ration straightforward and enabled the enrichment and analysis of proteins at low levels in proteomics samples. We demonstrate this by analyzing excis ed spots in a biological sample originating from a human fetal fibroblast c ell line that was subjected to 2D gel-electrophoresis. Furthermore, a sampl e deposition rate below 30 Hz results in an increased analyte density on th e dispensed sample spot, rendering signal amplification. In general, the se nsitivity for proteins and peptides can be enhanced 10-50 times compared to traditional MALDI sample preparation techniques. (C) 2001 Elsevier Science B.V. All rights reserved.