CHAPTER 3: Lesson 11: ASEPTIC TECHNIQUE Flashcards
What is the main objective of aseptic technique?
to eliminate contaminants from
work surfaces, solutions and other sources in the laboratory
Contamination can be avoided by the ff:
(1) regular checking of culture
(2)
avoidance of use of antibiotics for at least a part of incubation period to reveal cryptic
contaminations
(3) always use sterile reagents and materials, (4) exclusive use of
media, materials for different cell lines
(5) strict observation of standard sterile technique at all times.
Elements of aseptic environment
- Quiet area
- Work surface
- Personal Hygiene
- Reagents and media
- Cultures
In the absence of a laminar flow or sterile room, a this area with little
or no traffic and no other activity should be picked.
Quiet Area
The area should be kept clean
and not contain equipment other than that related to culture.
Quiet Area
Non sterile activities
should not be carried out in this area.
Quiet Area
Maintain clean and tidy ________ by (a) completely clear
surface, (b) swab surface with 70% alcohol before, between and after procedures, (c)
place onto the work surface materials necessary for a certain procedure, (d) arrange
work area systemically for easy access of items used and wide clear space to work
on, (e) work within range of vision, (f) mop up any spillage immediately and swab
area with 70% alcohol, and (g) when finished, remove all materials from the work
surface and swab with 70% alcohol.
Work surface
hand washing is encouraged to reduce bacterial
count/adherent microorganisms on the skin that would otherwise likely to blow onto
your culture and cause contamination.
Personal Hygiene
Surgical gloves may be worn and swabbed
frequently, and disposed properly after procedure.
Personal hygiene
Long hair are tied back or kept in a cap, avoid talking when doing a procedure if not working in a laminar
flow hood, or avoid doing any culture procedures when having any respiratory
symptoms.
Personal hygiene
This is encouraged to reduce bacterial
count/adherent microorganisms on the skin that would otherwise likely to blow onto
your culture and cause contamination.
hand washing
These are ensured to be sterile
within packages.
Reagents and media
Be cautious when handling these from other laboratories as they
may be contaminated from the source or during transit.
Cultures
Newly arrived should be handled separately from the rest of the stocks and avoid antibiotics until
they are shown to be uncontaminated.
Cultures
Sterile Handling
- Swabbing
- Capping
- Flaming
- Handling Bottles and Flasks
- Pipetting
- Pouring
swab surface with 70% alcohol before, between and after procedures.
Swab other materials if applicable before use.
Swabbing
Swab surface with this before, between and after procedures.
70% alcohol
Screw caps should be washed thoroughly and covered with aluminum foil
to protect neck of bottle from dust.
Capping
Type of steril handling wherein the neck of bottles and screw caps or other materials before and
after opening, before and after closing it to avoid contamination.
Flaming
when working on an open bench, these should not be kept vertical when opened and kept at an angle as shallow as
possible during manipulations to avoid contamination
Handling Bottles and Flasks
the easiest way to
manipulate liquids
Pipetting
It should be avoided to avoid mycoplasmal
contamination and prevent hazard to the operator.
Mouth pipetting
It should be avoided as much as possible to prevent generation of a bridge of
liquid between the outside of the bottle and the inside, which may permit contamination to enter the bottle.
Pouring
An equipment that protect work surface from dust and contamination by a
constant, stable flow of filtered air passing over the work surface.
Safety cabinets (Laminar Flow)
Two types of Safety cabinets (Laminar Flow)
• horizontal
• vertical
Where air blows from the side facing you, parallel to the work surface, and
not circulated;
horizontal
Where air blows down from the top of the hood onto the
work surface and is drawn through the work surface and either recirculated or vented.
vertical
These are used to sterilize the air and exposed work surfaces in laminar flow hoods between uses.
Ultraviolet lights
These are a major source of contamination.
Humidified incubators
Incubators should
be regularly cleaned with detergent and then swabbed with ________ and cleared
of any inappropriate contents.
70% alcohol
The humidifier tray at the bottom of the incubator can
be supplemented with a _______ to retard fungal growth.
fungicide
