Aseptic technique
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2008-04-02T17:07:32Z
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'''Aseptic technique''' refers to a procedure that is performed under sterile conditions. This includes medical and laboratory techniques, such as with [[microbiological culture]]s.
==Medical procedures==
Aseptic technique is the effort taken to keep patients as free from [[Nosocomial infection|hospital micro-organisms]] as possible (Crow 1989). The founder of the technique is considered to be [[Joseph Lister]]. It is a method used to prevent contamination of [[wound]]s and other susceptible sites by organisms that could cause infection. This can be achieved by ensuring that only sterile equipment and fluids are used during invasive medical and nursing procedures. Ayliffe et al. (2000) suggest that there are two types of asepsis: medical and surgical asepsis. Medical or clean asepsis reduces the number of organisms and prevents their spread; surgical or sterile asepsis includes procedures to eliminate [[micro-organism]]s from an area and is practised by nurses in operating theatres and treatment areas.
==In microbiology==
Aseptic technique is the name given to the [[procedure]]s used by [[microbiologist]]s to prevent microbial contamination of themselves, which may result in [[infection]], contamination of the [[Ecosystem|environment]] they are working in (e.g. [[fomite]]s), and contamination of the [[specimen]] they are working on, which is especially important when a [[pure culture]] is desired. It is used whenever specimens are to be transferred between media, for example, when [[Subculture (biology)|subculturing]]. Such a procedure, using a [[Bunsen burner|flame]] [[sterilization (microbiology)|sterilization]] method, might occur as follows:
[[Image:Test-tubes.jpg|right|thumb|100px|[[Test tube]]s]]
# A [[person]] would assemble the closed [[Test tube|tube]] or [[Laboratory flask|flask]] from which—and the closed tube or flask to which—the specimen is to be transferred, an [[inoculating loop]], and a fire source, all on a clean, preferably microbe-free surface with some overhead protection from [[wiktionary:airborne|airborne]] microbes.
# The person would start the fire, and move the end of the inoculating loop, in a slow back-and-forth motion, through the top of the [[flame#flame color|blue part of the flame]]. The person would not allow the loop to touch anything except the specimen itself, until the entire procedure is finished.
# Preparing to execute the specimen transfer, the person would hold both of the tubes or flasks in one hand, typically the opposite of the [[handedness|writing hand]]. The person would then open the tube or flask containing the specimen source and briefly hold the top of it in the flame, to kill unwanted microbes.
# Quickly, so as to minimize the possible time for contamination of the specimen in the source tube or flask, the person would use the inoculating loop with their writing hand to retrieve the specimen, and then sterilize the top of the tube or flask again before immediately closing it.
# Keeping in mind that the specimen on the inoculating loop could be contaminated during every moment it is exposed, the person would repeat the previous step identically with the tube or flask in which the specimen is to be deposited; however, the person would be depositing the sample ''into'' the tube or flask.
Students of microbiology are taught the principles of aseptic technique by means of hands-on laboratory experience. Practice is essential in learning how to handle the laboratory tools without contaminating them.
==References==
*[http://faculty.stonehill.edu/calmeida/pdfs/micro_ca2.pdf "MICROBIOLOGY: Classroom Assignment #2"], a [[Portable Document Format]] [[computer file]]
*[http://www.sciencebuddies.org/mentoring/project_ideas/MicroBio_Techniques.shtml Microbiology Techniques & Troubleshooting]
*[http://www.ruf.rice.edu/~bioslabs/bios318/318manual.htm#aseptic Methods Manual – Applied Microbiology: Aseptic Technique]
==See also==
*[[Antiseptic]]
*[[Contamination control]]
*[[Cleanliness]]
*[[Body substance isolation]]
==External links==
*[http://www.engenderhealth.org/ip/aseptic/at2.html Engender Health: Introduction to Aseptic Technique]
*[http://www.carringtonlabs.com/default.asp?contentID=154 Hand Washing & Aseptic Technique]
[[Category:Medical hygiene]]
[[Category:Microbiology techniques]]
[[pl:Aseptyka]]
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