Cell disruption

Cell disruption is a method or process for releasing biological molecules from inside a cell. The production of biologically interesting molecules using cloning and culturing methods allows the study and manufacture of relevant molecules. Except for excreted molecules, cells producing molecules of interest must be disrupted. This page discusses various methods. Another method of disruption is called cell unroofing. A common laboratory-scale mechanical method for cell disruption uses glass, ceramic or steel beads, 0.1 to 2 mm in diameter, mixed with a sample suspended in aqueous media. First developed by Tim Hopkins in the late 1970s, the sample and bead mix is subjected to high level agitation by stirring or shaking. Beads collide with the cellular sample, cracking open the cell to release intercellular components. Unlike some other methods, mechanical shear is moderate during homogenization resulting in excellent membrane or subcellular preparations. The method, often called "bead beating", works well for all types of cellular material - from spores to animal and plant tissues. It is the most widely used method of yeast lysis, and can yield breakage of well over 50% (up to 95%). It has the advantage over other mechanical cell disruption methods of being able to disrupt very small sample sizes, process many samples at a time with no cross-contamination concerns, and does not release potentially harmful aerosols in the process. In the simplest example of the method, an equal volume of beads are added to a cell or tissue suspension in a test tube and the sample is vigorously mixed on a common laboratory vortex mixer. While processing times are slow, taking 3-10 times longer than that in specialty shaking machines, it works well for easily disrupted cells and is inexpensive. Successful bead beating is dependent not only on design features of the shaking machine (which take into consideration shaking oscillations per minute, shaking throw or distance, shaking orientation and vial orientation), but also the selection of correct bead size (0.