The bacteria do not lyse with B-PER reagent. What is the problem?
Bacteria grown in rich medium (high glucose) are difficult to lyse. Try reducing the glucose concentration. Bacteria and organisms lysed with B-PER Reagent include E. coli, Acetinobacter, Archaebacteria, S. aureus, H. pylori, Baculovirus, nematodes and insect cells. B-PER Reagent can lyse some gram positive bacteria, but tends to be more efficient with gram negative bacteria. If lysis is inefficient for a particular bacterial strain, freeze cells before extraction. Add lysozyme for the most efficient extraction, however, for some over-expressed proteins the addition of lysozyme is not required.
