Using Aseptic Technique to identify the effect of antibiotics on 3 strains of Bacteria - It's use and procedure- Year 12 Biology 2014
To become familiar with Aseptic Technique and to use
it to plate bacterial cultures.
1. I can organise my work area in a safe manner
taking into consideration the requirements for
2. I can open and close bacterial culture tubes without
putting the lid down on the bench.
3. I can plate bacteria onto the agar without
damaging the agar.
4. I can apply the mastring
5. I am confident using Aseptic Technique
Aseptic technique refers to a procedure that is
performed under sterile conditions. This
includes medical and laboratory techniques
which deal with cultures and human cells and
tissue for transplantation. The largest example
of aseptic techniques is in hospital operating
theatres. It is used to stop the spread of
Flame sterilization - metal loops used for picking up cultures , forceps
and the necks of glass/plastic reciprocals are flamed to prevent microbial
Reducing the time in which microbial samples and sterilised instruments
have contact with the air
The use of an autoclave or pressure cooker to sterilise growth media and
broths and also non-metal/ glass instruments such as plastic spreaders
Ensuring your work space and yourself is cleaned with appropriate
cleaning substances and disinfectants.
The main aim is to prevent the contamination from you to your
environment and from the environment to you and therefore the possible
spread of the contaminant outside of the laboratory.
flow cabinets pass
the filtered air across
the work and out
into the room.
1. Work in groups of three. Each person plates
a different bacteria.
2. Collect equipment: laboratory coat, gloves,
bunsen burner, matches, swabs x3, disinfectant,
disposable, 3 nutrient agar plates, marker,
masking tape, mastring, bacterial cultures to be
shared amongst class, beaker containing
disinfectant for used swabs, forceps.
3. Disinfect your work area- working from back
4. Arrange equipment as shown in demonstration.
5. light Bunsen Burner and flame the top of the
bacterial culture tube. Remember to hold the cap
in your little finger. Do not put it down on the
6. Insert the swab and soak up some of the
bacterial broth culture.
7. Remove and reseal the tube with the lid.
8. Still holding the swab, open the petri dish and
very gently spread the bacteria over the nutrient
agar as demonstrated.
9. Close the petri dish lid and place the infected
swab into the beaker containing disinfectant.
10. Flame the forceps and carefully pick up a
mastring at the white tab part only.
PG- Penicilin G
S – Sulphatriad
St - Streptomycin
T - Tetracycline
Ap – Ampicillin
11. Ensure all the disks are in contact with the agar
by gently tapping only the white spaces on the
12. Close the petri dish lid.
13. Flame the forceps.
14 Label the petri dish with your initials, the name
of the bacteria, incubation time (48hrs), incubation
temperature (30o), and date.
15. Seal plate with masking tape.
16. Place all plates at the front of the class.
17. pack away equipment.
18. Disinfectant your work area.
19. Wash your hands with soap and water.
E Coli –Escherichia coli
Staph Albus - Staphylococcus albus
B Subtilis -Bacillius subtilis
Nomenclature of bacteria refers to naming bacteria and other
organisms according to the binomial system, which was
introduced by Carl Linnaeus (1674-1748).
A bacterium has a species name, composed of a genus name that
tells you to which genus it belongs and a species epithet which,
together with the genus name, is unique to the bacterium.
An example is Moraxella bovis, where the genus name indicates
that the bacterium belongs to the genus Moraxella and the species
name indicates that the bacterium has been isolated from cattle.
The genus name and the species epithet form the scientific name
of the species, which is always written in italics, with a capital
letter starting the Genus name only. The species name is always
written in lower case.
1. What is a control and what is it used for?
2. Why are the cultures incubated at 30o and
3. Why is it important not to touch the
4. What is the purpose of flaming the culture
tube before and after insertion of the swab?
5. Why should there be minimal talking and
moving around whilst performing this
6. Describe how the plates should be disposed
of and why?
- 3 things I have learnt today……….
- 2 new words I can add to my Biology vocabulary
list and there meaning……………………
- My understanding of aseptic technique is …….