Use of surface-enhanced laser desorption/ionization -time of flight to explore bacterial proteomes.

Surface-enhanced laser desorption/ionization (SELDI)-time of flight is a recent technology that allows proteomic analysis with limited material requirements. This characteristic makes it a valuable technique for microbiologists handling problematic samples, such as low cell number cultures. We compared three simple procedures for protein extraction from bacteria for compatibility with the ProteinChip Array; we also determined the amount of protein required for each analysis. The protocol for the SELDI analysis was evaluated by generating protein expression profiles of a Streptococcus pneumoniae strain grown in different conditions and those of different strains of the same species. The protocol also was successfully applied to a wide range of Gram positive and negative bacteria. The results of this study suggest the appropriateness of this technology for microorganism protein profiling as complementary or alternative to two-dimensional gel electrophoresis.