Aseptic technique refers to a procedure that is performed under sterile conditions. This includes medical and laboratory techniques, such as with
microbiological cultureA microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
s.
Aseptic technique is the effort taken to keep patients as free from
hospital micro-organismsNosocomial infections are infections which are a result of treatment in a hospital or a healthcare service unit, but secondary to the patient's original condition. Infections are considered nosocomial if they first appear 48 hours or more after hospital admission or within 30 days after discharge...
as possible (Crow 1989).It is a method used to prevent contamination of
woundIn medicine, a wound is a type of injury in which skin is torn, cut or punctured , or where blunt force trauma causes a contusion . In pathology, it specifically refers to a sharp injury which damages the dermis of the skin.-Types of wounds:-Open:Open wounds can be classified according to the...
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.
Aseptic technique refers to a procedure that is performed under sterile conditions. This includes medical and laboratory techniques, such as with
microbiological cultureA microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
s.
Medical procedures
Aseptic technique is the effort taken to keep patients as free from
hospital micro-organismsNosocomial infections are infections which are a result of treatment in a hospital or a healthcare service unit, but secondary to the patient's original condition. Infections are considered nosocomial if they first appear 48 hours or more after hospital admission or within 30 days after discharge...
as possible (Crow 1989).It is a method used to prevent contamination of
woundIn medicine, a wound is a type of injury in which skin is torn, cut or punctured , or where blunt force trauma causes a contusion . In pathology, it specifically refers to a sharp injury which damages the dermis of the skin.-Types of wounds:-Open:Open wounds can be classified according to the...
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-organisms from an area and is practiced by surgical technologists and nurses in operating theaters and treatment areas. In an operating room, while all members of the surgical team should demonstrate good aseptic technique, it is the role of the 'scrub nurse'(usually a surgical technologist)to set up and maintain the sterile field.
In microbiology
Aseptic technique is the name given to the
procedureProcedure may refer to:* Procedure * Algorithm, in mathematics and computing, a set of operations or calculations that accomplish some goal* Instructions or recipes, a set of commands that show how to prepare or make something...
s used by
microbiologistA microbiologist is a scientist who works in the field of microbiology. Microbiologists study organisms called microbes. Microbes can take the form of bacteria, viruses, fungi, and protists...
s to prevent microbial contamination of themselves, which may result in
infectionAn infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the...
, contamination of the
environmentAn ecosystem is a system of interdependent organisms which share the same habitat, in an area functioning together with all of the physical factors of the environment. Ecosystems can be permanent or temporary. Ecosystems usually form a number of food webs...
they are working in (e.g. fomites), and contamination of the
specimenIn biology, a specimen is an individual animal, part of an animal, plant, part of a plant, or microorganism used as a representative to study the properties of the whole population of that species or subspecies...
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
subculturingIn biology, a subculture is either: a microbiological culture made by transferring microorganisms from a previous culture to a fresh growth medium, a method used to prolong the life of a particular strain of microorganism where there is a tendency of degeneration in older cultures; or a fresh...
. Such a procedure, using a
flameA Bunsen burner is a common piece of laboratory equipment that produces a single open gas flame, which is used for heating, sterilization, and combustion.- History :...
sterilizationSterilization refers to any process that effectively kills or eliminates transmissible agents from a surface, equipment, article of food or medication, or biological culture medium. Sterilization does not, however, remove prions...
method, might occur as follows:
- A person
A person is a legal concept both permitting rights to and imposing duties on one by law. In the fields of law, philosophy, medicine, and others, the term has specialised context-specific meanings....
would assemble the closed tubeA test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top, usually with a rounded U-shaped bottom...
or flaskLaboratory flasks are vessels which fall into the category of laboratory equipment known as glassware. In laboratory and other scientific settings, they are usually referred to simply as flasks...
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 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 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 writing hand
Handedness is an attribute of humans defined by their unequal distribution of fine motor skill between the left and right hands. An individual who is more dexterous with the right hand is called right-handed, and one who is more skilled with the left is said to be left-handed. A minority of people...
. 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.
See also
- Antiseptic
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
- Contamination control
Contamination control is the generic term for all activities aiming to control the existence, growth and proliferation of contamination in certain areas...
- Cleanliness
Cleanliness is the absence of dirt, including dust, stains, bad smells and garbage. Purposes of cleanliness include health, beauty, absence of offensive odor, avoidance of shame, and to avoid the spreading of dirt and contaminants to oneself and others. In the case of glass objects such as...
- Body substance isolation
Body substance isolation is a practice of isolating all body substances of individuals undergoing medical treatment, particularly emergency medical treatment of those who might be infected with illnessess such as HIV, or hepatitis so as to reduce as much as possible the chances of transmitting...
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