Sonication cell rupturing

The desired concentration of cells is often a function of how the cells will be processed. For example, cell rupture by sonication is most effective in a narrow cell concentration range. 

For solid materials, it is first necessary to homogenize the sample. This can be accomplished only after the physical structure of the sample is destroyed. This can be as simple as grinding seeds in a mortar and pestle or using a food blender to create a puree from a sports nutritional bar. Additionally, one may wish to sonicate the sample to rupture cells and release their content. A review that also discusses more stringent methods for homogenization (e.g., hammer milling, C02 milling) is presented by Lichon (6). 

The initial step in purifying subcellular structures is to rupture the plasma membrane and the cell wall, if present. First, the cells are suspended in a solution of appropriate pH and salt content, usually isotonic sucrose (0.25 M) or a combination of salts similar in composition to those in the cell s interior. Many cells can then be broken by stirring the cell suspension in a high-speed blender or by exposing it to ultrahigh-frequency sound (sonication). Plasma membranes can also be sheared by special pressurized tissue homogenlz-... 

One problem in production of recombinant proteins is recovery of the finished product from the cells which accumulate it. This problem is particularly acute in the case of yeasts and fungi, which have tough, thick cell walls which are difficult to rupture mechanically or by sonication. Product secretion is not always feasible, even for low-molecular-weight products, although a newly developed secretion process for yeast (7) appears promising. 

Cell Lysate An extract containing cellular contents obtained after rupturing cells by various means such as freeze-thaw, sonication, enzymatic, or osmotic mechanisms. 

Ultrasound (sonication) This is a chemical-free process to cause cell disruption by inducing cavitation (bubbles) into a solution. The bubbles generate turbulence and pressure differences during both formation and bursting that can lead to rupture of microorganisms. The technique is still under research. 

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