1. A method of determining if proteins have been transferred from liquid-phase protein fractions to an array, the method comprising staining the array with a total protein stain and imaging the array with an array imager, wherein staining is indicative of the transfer of protein to the array, and wherein the liquid-phase protein fractions are obtained from a whole cell lysate using two-dimensional liquid-phase fractionation, and wherein the array is a gel element protein array.