A common question on Internet message boards dealing with protein methods is which cell lysis method is the most efficient, or the quickest, or the easiest. The answers are seemingly as varied as the number of proteins in the proteome. The best method is the one that works.
After attempting (unsuccessfully) to lyse yeast using a commercially available chemical lysis kit, we moved on to a mechanical lysis method using glass beads and the Beadbeater from BioSpec.
The Beadbeater can be used with volumes as little as 15 mL or as large as 250 mL. It comes with a high speed mixing unit (really just the base of a blender) and a bead chamber. Additionally, a cooling jacket for the bead chamber comes with the unit. Bead chambers of varying volumes (from 15 – 250 mL) can be purchased. This allows the researcher to easily scale up production.
The procedure is quite easy and painless. After centrifuging my culture, I resuspended the pellet in 15 mL lysis buffer (PBS with Triton X-100 and SDS). To the bead chamber I added 15 mL glass beads and then the 15 mL of lysate. After capping the bead chamber tightly, I inverted the chamber into the cooling jacket filled with ice water. A collar was then screwed on and the assembly was placed on the mixer. The cells were lysed over four 30 second on/30 second off cycles. Once the bead chamber was removed from the cooling jacket, I let the glass beads settle for a few seconds before uncapping the chamber. After pipetting off the lysate, I poured the beads over nylon mesh and rinsed them with water. The final step was to place the beads in a beaker with a mild detergent, washing them for about 20 minutes while agitating with a stir bar. After rinsing in ddH2O, I put them in a 60oC incubator to dry overnight.
BioSpec claims that about 90% of cells in the bead chamber will be lysed. We indeed found that our yield of protein was much higher after using the Beadbeater than after the chemical lysis procedure we had used previously. Overall I would have no problem recommending this product to anyone interested in an efficient, fast way to lyse yeast for protein purification.
J. Jason Clark
Research Assistant
University of Iowa