Tissue samples from human tonsils and rat pancreas were subjected to a novel laser-based homogenization method, the PIRL-DIVE homogenization, and to a conventional mechanical tissue homogenization procedure (bead mill and a cryo-grinder). The protein species composition of the protein extracts were compared by differential proteome analysis using two-dimensional gel electrophoresis followed by LC-MS/MS analysis and one-dimensional gel electrophoresis (SDS-PAGE) followed by quantitative LC-MS/MS analysis.