Aseptic Technique

Brief Description:

 

Aseptic technique involves handling a microbial sample in a manner which prevents contamination. This is important for preventing sample contamination and protecting people in the lab from exposure to pathogens. This technique is important for plating isolated colonies to purify a culture and avoid contamination or transferring microbes to be viewed under the microscope. All materials in contact with the culture must be sterile. When preparing to transfer a sample, a sterile inoculating loop is used. It can either be a disposable loop or a wire loop flamed over a Bunsen burner. The loop must be cool enough to not kill the organisms on contact. Caps and lids should be held over plates and test tubes while being used in order to avoid airborne contaminants. Bacteria from human skin are also a source of contamination and it is important to wear sterile gloves and a lab coat and tie back hair if necessary.

Application in Wine Microbiology:

Aseptic technique is important for wine microbiology for identifying and culturing organisms. Yeast cultures sold commercially must have a certain level of purity and to obtain that, yeast must be cultured and isolated aseptically. Wines with spoilage characteristics can be studied for microbial growth to identify the spoilage organism. The organisms must be isolated using aseptic technique or it is possible to culture an organism that may not have been found in the wine. Aseptic technique allows scientists to isolate and study individual organisms within a wine or must. Wine with residual sugar must be bottled aseptically, or organisms introduced can grow in the bottle and cause spoilage.

References:

  • Coté . R.J. 1998. Aseptic Technique for Cell Culture. Current Protocols in Cell Biology (1998) 1.3.1-1.3.10. John Wiley & Sons, Inc.
  • Jacobson, J.L. 2006. Introduction to Wine Laboratory Practices and Procedures. Springer Science and Business Media.
  • Kunkee, R.E. and G.M. Cooke. 1980. 100 years of wine microbiology. California Agriculture.