The US Patent and Trademark Office has awarded Genomic Solutions US patent 6,302,159, entitled “Apparatus and method of carrying out flow through chemistry of multiple mixtures.” The patent covers technology developed by Genomic Solutions for its ProPrep and ProGest instruments, which prepare samples of proteins picked from 2D gels for mass spectrometry analysis. Specifically, the patent describes a technique for evacuating reagents from 96-well trays without the use of a syringe.