Disrupting Escherichia coli: a comparison of methods.

The often-encountered problem of disrupting bacteria for the purpose of extracting soluble protein has generated various methods. Many require specialized equipment. Very often, especially during preliminary studies, investigators need a simple, fast, and inexpensive method for cell disruption that preserves biological activity. This paper compares some simple and inexpensive methods for cell disruption, such as bead-vortexing, freezing-thawing, French pressing, and sonication. It also provides some tips to increase protein yield and preserve biological activity. If performed under optimal conditions, bead-vortexing gives protein yields that are comparable to French pressing and sonication. It also preserves the activities of labile enzymes and releases periplasmic enzymes. Vortexing with glass beads appears to be the simplest method for cell disruption.