MORETON BAY COLLEGE
Science Department.
MICROBIOLOGY LABORATORY POLICY AND PROTOCOLS
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HAZARDS
Routes of exposure to microorganisms may occur via skin abrasions, cuts or
puncture wounds, inhalation of aerosols, or ingestion via contaminated hands or
materials.
Exposure may involve the individual staff or students using the micro-organisms,
other staff and students using the same laboratory or work area, cleaning staff, or
the wider community.
The outcome following exposure depends on the pathogenic level of the
microorganism involved, the exposure level, and the route of exposure.
RISK ASSESSMENT
Whenever microbiology is studied there are potential risks from the hazards of
infection. It is through the establishment of correct and appropriate protocols and
the strict adherence to these procedures which enables students and staff to work
safely with microorganisms. This includes selecting the appropriate level of practical
activity for the student age group, clear safe working protocols (SOP’s), the facilities
available, and the level of training and experience of the teacher and the laboratory
technician.
Standard operating procedures (SOPs) must be documented within a risk
assessment for all activities undertaken and these must be strictly adhered to.
Procedures should be such that the risk of contamination to: the air, to laboratory
benches and furniture, to the student and staff working with the bacteria, to other
students and staff, or to the wider community and the environment, is suitably
reduced.
These procedures should include the equipment and facilities required in
preparation, experimental techniques, and clean-up and disposal. The procedures
must also include emergency plans for spills and first aid. These are outlined at the
end of this document.
GENERAL CONTROL MEASURES.
Each of these aspects must be considered in the risk assessment.
Student age and maturity
It is important that the teacher is confident that the students planning on working with
microorganisms will be able to have a full appreciation for the risks and be
disciplined in following the standard operating procedures.
Experience
It is important that the teacher and the laboratory technician has an appropriate level
of competence in preparation, sterilization, and disposal of materials. (See detail
below under - Appropriate Activities for Various Year Levels)
High Risk Persons.
Persons can be immuno-compromised, immuno-suppressed, due to a medical
condition or medical treatment they are receiving. Others may be unduly vulnerable
to infection such as persons who are diabetic and pregnant women. These people
(students or staff) need to be identified and then managed appropriately. The
management should be consultative and based upon professional medical advice.
Selection of Media
Standard nutrient broth or nutrient agar is sufficient for school culture work. [Media
designed to select pathogens (e.g. blood agar, McConkey etc.) must not be used].
Selection of Bacteria
The College will only use Risk Group 1 micro-organisms (as defined in AS2243.3
Safety in Laboratories – Microbiology Aspects and Containment Facilities) – being
those that pose low individual & community risks. These are microorganisms that
are unlikely to cause human, plant or animal disease. The organisms for use in the
College are limited to bacteria. (see appendix 1). Viruses and fungi will not be
used.
The College will only purchase these micro-organisms from Southern Biological
Supplies which has been deemed a reputable supplier. Other suppliers may be
considered at the discretion of the Laboratory Technician and Laboratory Manager.
Potential to be Pathogenic
All microorganisms shall be treated as potential pathogens. Even microorganisms
not normally associated with human diseases, are ‘opportunistic’ pathogens and may
cause infection in the young, the aged and in immune-deficient or immunesupressed individuals. In addition, samples may become contaminated or may
mutate.
Contain all organisms at each stage of the procedures as if they were of higher risk.
Size Limitations
Cultures should be kept to the minimum size and number required to achieve
meaningful results.
Incubation Temperature
The incubation temperature should be restricted to an upper limit of 30OC to reduce
the danger of isolating pathogens adapted to human body temperature.
Anaerobic conditions should also be avoided for the same reason.
Aerosols
Aerosols (particles of liquid containing microorganisms suspended in the air) can
easily contaminate the laboratory if procedures are poor. Care must be taken when
flaming loops, opening bottles, using pipettes and any other procedure that may
produce aerosols. Spills may also cause aerosols. (See sections on Spills and First
Aid)
If there is clearly an identified risk of a procedure producing aerosols, then the
technique should not be used, or the work should be carried out in a biological safety
cabinet.
Culturing from the Environment
The College does not permit students to culture organisms taken from the
environment. This includes samples from bodies of water, soils, atmosphere, toilet
areas, door handles etc.
If microorganisms are cultured from the environment there is the possibility of
isolating unknown high risk pathogens.
Extra Laboratory Rules for Microbiology:
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Avoid habits of putting hands or objects anywhere near the mouth of eyes.
Teacher should warn students pro-actively.
Staff & students must always wear specific laboratory coats/aprons while in the
laboratory. These coats/aprons are provided by the College and will be stored on
hangers in the laboratory for duration of project of work, after which time they will
be properly laundered. The laboratory coats must not be worn outside the
laboratory.
All cuts or broken skin must be covered by a water resistant dressing eg a BandAid and gloves. Teacher will ask all students prior to starting work each day.
Benches should be clear of all non-essential materials including books and notes.
Following any practical work with the microorganisms, benches should be wiped
with a suitable disinfectant eg. 0.1% solution of sodium hypochlorite (available
Cl), or 70% alcohol. Wearing gloves, spray disinfectant over bench surface,
wipe off with cloth and dispose.
Teacher must ensure all hands are washed with soap and water at the
designated hand wash sink before leaving the laboratory. Hands must also be
washed after removing gloves, following clean-up of a spill. (See section on
Correct Hand Washing Techniques)
APPROPRIATE ACTIVITIES FOR VARIOUS YEAR LEVELS
Year 7
Only microorganisms with little, if any, known risk should be used. e.g. observation
of moulds, yeasts and algae. These should be observed in closed containers that the
students cannot open.
No special training is required for the teacher or laboratory technician.
Years 8-10
At this level, culturing techniques with known organisms from reputable suppliers.
All petri dishes must be sealed following inoculation & during examination.
At this level, both the teacher & the laboratory technician require a working
knowledge of aseptic technique, safe disposal technique and must be able to
recognise contamination. This level of knowledge would be acquired from a short inservice course in microbiology.
Seniors - Year 11-12
At this level, application of inhibitory substances to cultures and sub-culturing and
transfer procedures using known organisms are appropriate.
If carrying out sub-culturing, both the teacher & the laboratory technician require
good aseptic technique. This can only be provided through training & practice
extending beyond the level of a short course.
Work should not be carried out by non-specialised staff or if appropriate facilities are
not provided.
FACILITIES
MBC has a modern Microbiology Laboratory [R6 ] designed to meet requirements of
PC2 (physical containment level 2) as specified in AS 2243.3. This exceeds that
required to work with risk group 1 microorganisms.
The facility offers protection with:
 Fully coved seamless vinyl flooring which reduces crevices and ledges which are
hard to disinfect.
 Easily cleaned bench surfaces and floor area with minimal fixed under bench
cabinetry or cupboards.
 Sensor operated tap at hand wash basin.
 Negative pressure air flow system.
 Smooth water impervious ceiling tiles.
 Autoclave in adjoining preparation room.
Work with the risk group 1 micro-organisms must only be carried out in the
Microbiology Laboratory.
PREPARATION & STERILISATION OF EQUIPMENT
Sterilization. (killing of all microbiological life including bacterial and fungal spores)
The College uses a bench top autoclave which is located in the adjoining preparation
room to the microbiology laboratory. This is operated only by the laboratory
technician, who had been trained in its operation and will follow the safe operating
procedures.
The Laboratory Manager shall ensure the autoclave is regularly maintained.
Items should be sterilised at 121 OC and 15 psi. (or 103kNm-2) for 15 minutes.
As a back-up to the autoclave the use of a pressure cooker following established
safe operating procedures is possible, keeping in mind this will only disinfect and not
sterilize, although this is still adequate for the level of work at MBC.
Refer to Standard operating procedures for more detail and instruction on autoclave
use.
Disinfecting. (Likely to kill all but the most resistant microorganisms such as Tetanus
bacterial spores).
Disinfectants
The following 2 disinfectants are suitable for use on benches, surfaces and
equipment. They should be applied as a spray according to the standard operating
procedure.
Alcohols (good activity on bacteria, and fungi but less on viruses and poor activity on spores.
 70% ethanol is rapid acting and dries quickly. (100% ethanol is NOT effective)
 60-70% Isopropyl alcohol (Propan-2-ol).
Sodium Hypochlorite (good activity on bacteria, fungi and viruses, but less activity on spores).
They must be prepared fresh daily from the concentrated stock solution to ensure
the correct level of available chlorine.
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1% available chlorine for spills,
0.25% for discard jars,
0.1% for cleaning benches, and
0.05-0.1% for equipment and instruments.
The following disinfectant may be used for hands and skin.
Chlorhexidine (good activity on gram-positive bacteria but less activity on gram-negative
bacteria, viruses and fungi and poor activity on spores).
It has low toxicity and irritancy and so is a good antiseptic. 0.5% for face - 4% for
other skin.
The Safety Data Sheet for the disinfectants used must be consulted for appropriate
technique, protective equipment and ventilation requirements.
SAFE BACTERIA HANDLING TECHNIQUES
These procedures are for use by the laboratory officer, teachers and students.
Teachers should fully explain and demonstrate all techniques that the students will
use, giving particular attention to safety and good aseptic technique.
Students must have been be taught good aseptic technique prior to experimentation.
Techniques - safe techniques for the following are described in the Standard
Operating Procedures section below.
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Plating Broth Cultures Using Wire Loops.
Preparing a Bacterial Lawn for Antibiotic Discs.
Observation of Plates
Microscopic Examination of Bacteria
Disposal and Clean-up.
The most important bacterial infection control is that of always carefully following,
systematic and pedantic technique. This applies to the handling of equipment used,
disposal of consumables and cultures themselves, and personal cleanliness.
Detailed procedures for the following cleaning and disposal tasks are outlined in the
Standard Operating Procedures section below.
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General Clean-up
Glassware
Broth Cultures
Petri Dishes.
Incubator.
References:
Microbiology – Safety Considerations 1999
Sheryl K. Hoffmann, B Sc., Grad Dip. O. H., MSIA Concordia College
Laboratory Officer,
Concordia College,
45 Cheltenham St,
HIGHGATE SA 5063
Standards Australia, AS2243.3- 2002 Safety in Laboratories. Part 3. Microbiological Aspects and
Containment Facilities.
APPENDIX 1
List of Bacteria Risk Group 1
Acetobacter aceti
Bacillus subtilis
Chromatium species
Escherichia coli *
Micrococcus luteus (=Sarcina lutea)
Pseudomonas fluorescens**
Rhodopseudomonas palustris
Staphylococcus albus (epidermidis)**
Streptomyces griseus
Agrobacterium tumefaciens
Chromobacterium lividum
Erwina carotovora (=E. atrospetica)
Lactobacillus species
Photobacteium phosphoreum
Rhizobium leguminosarum
Spirillum serpens
Streptococcus lactis
Vibrio natriegens (=Beneckea natriegens)
Additional information for consideration when completing the risk assessment.
* Some strains have been associated with health risks. Reputable suppliers will ensure that
acceptable strains are provided.
** These organisms have been known to infect debilitated individuals and those taking
immunosuppressive drugs.
The following microorganisms have previously been used in schools but are no
longer considered appropriate. These must not be used at the College.
Aspergillus nidulans
Chromobacterium violaceum
Penicillium chrysogenum
Pseudomonas aeruginosa
Pseudomonas tabacci
Staphylococcus aureus
Aspergillus niger
Clostridium perfringens (welchii)
Penicillium notatum
Pseudomonas solanacearum
Serratia marcescens
Xanthomonas phaseoli
List taken from: Department of Education and Science, 1985, Microbiology: An HMI Guide for Schools and Non-advanced Further
Education, Her Majesty’s Stationery Office, London, pg 20 /21.
STANDARD OPERATING PROCEDURES
STERILIZATION.
Autoclave.
The College autoclave is a bench mounted Siltex, with steam generating water tank
on board. Autoclave is located in Biology prep room adjoining microbiology lab.
This model will autoclave at 140oC at a pressure of 15 bar or 220KPa, while 120oC is
sufficient for effective sterilization of any risk group level 1 Bacteria.
Ensure autoclavable bags used are rated to 140oC and not just 120oC, otherwise
they will melt.
Users must be suitable trained to use the autoclave by the Laboratory Manager.
The autoclave should be maintained regularly.
Autoclave Operation
1. Check the internal water reservoir is near to full. (port on top back left of unit).
If necessary add tap water.
2. Fill the sterilizing chamber with water from the internal reservoir by pulling
down on the fill / vent lever (front top left). The chamber is sloped backwards
so fill until water line is 5omm from the front edge.
3. Load material to be sterilized into tray which will sit just above the water line.
4. Push the door closed and manoeuvre until the safety locking pin can be
securely located into place. Then turn the locking handle clockwise until
hand tight.
5. Set the timer dial to 20 minutes, and turn power on at the wall.
6. To start - push the switch at bottom to the ‘on’ position (left). The yellow LED
should light up.
7. The autoclave now be starting to heat the water and build pressure. Do not
touch any controls now until cycle finished.
8. It will take approximately 15 minutes for the temperature and pressure to be
reached at which time the sterilization period (20 minutes) will commence.
(The green sterilizing LED indicator should light up at this stage).
9. Monitor the gauges to check that 140oC and 220 – 230KPa are holding during
the cycle.
10. The buzzer alarm will indicate when the 20 minutes is completed.
11. Slide the switch at the bottom to off.
12. Release pressure gradually by gently and intermittently pulling down on the
fill / vent lever (front top left). Pull the lever down briefly, release, pull down
again, release, etc repeatedly until the pressure gauge indicates zero. You
will also hear the steam being released back through the water reservoir until
the pressure is fully released.
13. It will now be safe to open the chamber door by winding the handle anticlockwise. If the handle will not turn then there is still pressure in the system.
14. Remove the locking pin and carefully open the door to remove autoclaved
materials. MIND they could still be hot - it is a good idea to just slightly open
the door and allow to cool before handling.
Materials in autoclave
 Do not wrap or cover items with foil as this impedes the steam penetration.
 Schott bottles should have lids on loosely to allow steam inside.
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Special autoclave bags rated to 140oC available from medical suppliers are to be
used.
Extreme care must be taken when sterilising liquids, the exhaust valve should not
be opened quickly or bottles may explode.
Siltex AUTOCLAVE
Fill/ vent lever
Water chamber port
Pressure gauge 220KPa
Timer and control panel
Chamber door
Door locking pin
Sterilizing Pipettes.
Prior to use: Pasteur pipettes should be plugged with non-absorbent cotton wool and
any protruding fibres burnt off. They are then wrapped in brown paper or foil,
alternatively they can be placed in pipette canisters or test tubes and the ends of the
test tubes sealed with paper or foil and masking tape. They can then be sterilised in
a dry heat oven at 160 OC for at least 1 hour, allowing adequate time to reach the
correct temperature. Temperatures over 170 OC will char brown paper and cotton
wool.
Similarly graduated pipettes may be plugged, wrapped and sterilised.
After use, pipettes should be immediately immersed in a container of
disinfectant and sterilised before disposal or washing. (A 600 ml tall beaker or a 2L
plastic measuring cylinder makes a good discard jar.)
Sterilizing Swabs
Prior to use: Cotton buds can be wrapped in brown paper and autoclaved or
wrapped in foil/ brown paper and dry heat sterilised as above. Some cotton buds are
treated with anti-microbial agents and it is usually more reliable to use hospital grade
swabs, available from medical supply companies.
After use, swabs should be immersed in a container of disinfectant and
sterilised before disposal.
Sterilising Test Tubes & Other Glassware
Prior to use: Test tubes and other glassware should be plugged with cotton wool
and capped with foil or brown paper, and then sterilised by dry heat as above.
McCartney bottles and Schott bottles do not require cotton wool plugs and should
just have their lids screwed on firmly and then released a quarter turn, prior to
sterilisation.
After use, glassware should either be placed in disinfectant or autoclaved prior to
cleaning.
Sterilising Loops
Wire loops for transfer of bacteria can be made from 24 swg nichrome wire
held in chuck needle holders or glass tubing that has had the wire inserted and the
neck sealed closed by the application of heat.
Loops are sterilised by heating to red hot in a Bunsen flame.
Safety - Flame heating loops carrying a culture may splatter and produce aerosols or
eject clumps of microorganism on the bench. To avoid this, loops should be drawn
slowly from the cooler to the hotter part of the flame.
The loops should also be cooled before use (e. g. on a vacant part of the agar plate)
to prevent killing the bacteria that you wish to culture.
Alternatively the loop may be dipped in 70% alcohol and then flamed.
Loops are sterilised just prior to and immediately following use.
Alternatively - plastic commercial loops may also be used which are placed into a
designated bag / container ready for sterilizing in the autoclave.
Sterilising spreaders & forceps
Spreaders are L-shaped glass rods used to spread a liquid culture evenly over a
petri dish.
Spreaders and forceps are sterilised by dipping them in alcohol and lighting the
alcohol in a Bunsen flame. The alcohol is allowed to burn off before use.
Spreaders may break if held in the Bunsen for too long.
Spreaders and forceps are sterilised just prior to and immediately after use.
PREPARATION OF AGAR PLATES
The College will generally purchase pre made agar plates form Southern Biological.
However the method for preparation of the plates is outlined below.
Following the instruction on the jar, (grams per litre) the powdered agar media is
added to water in a large conical flask. It is heated until the agar dissolves at 95 OC.
(This is best done in a water bath e.g. a saucepan of water on a hotplate.
Alternatively be sure to mix the contents well or uneven heating may crack the
flask. The agar solution is then poured into Schott bottles and the lid closed firmly
then released a quarter turn. Alternatively the agar may be poured into conical flasks
and plug with cotton wool and cover with brown paper.
The bottles/flasks are then sterilised in an autoclave or pressure cooker for 15
minutes at 121 OC & 15 p.s.i. (a microwave method for sterilisation is also available)
The agar is allowed to cool to 50-55 OC. (NB: Agar will not set above 42OC) Plastic
disposable petri dishes are lined up on the bench, in a draft free room. NB: It is not
recommended that glass petri dishes be used. Air-conditioners, fans and fume
cupboards must be turned off, windows and doors closed and foot traffic restricted,
to reduce the chance of contamination to plates while pouring. The bottle/flask is
unscrewed or unplugged and held at an angle. The lid from a petri dish is lifted just
enough to allow the agar to be poured in. This is repeated for the other dishes until
all the agar is used.
Approximately 25 ml of agar per dish is ideal. The agar is allowed to set before
repacking in plastic bags and storing in the fridge in an inverted position until
required. (see Figure 1)
The alternate recipe for Nutrient Agar preparation, used in the Microwave Method,
PLATING BROTH CULTURES USING WIRE LOOPS.
The lid/plug of the culture bottle/flask is held in the little finger. (never placed on the
bench) The bottle's neck is then passed through a Bunsen flame. (See Figure 3)
A wire loop is heated to red hot in the Bunsen flame and then dipped into the broth
culture carefully. Splattering may occur if the loop is not allowed to cool slightly
before use.
A loop full of culture is transferred to the agar plate. The loop is spread over the
surface of the plate. (see Figure 4) If individual colonies are required the pattern
illustrated in Figure 5 is used. The loop is then re-flamed and the neck of the culture
bottle is passed through the Bunsen flame before the lid/plug is re-fitted.
Figure 3 Flaming the Neck of a flask & Holding a Cotton Plug with the Little Fingers
Sterile Cotton Buds.
If you are using a pre-sterilized cotton bud, then you will clearly not be flaming the
bud, but you still flame the neck of the flask containing the culture.
Fig 4 General Spreading Pattern
Fig. 5 Spreading Pattern for Individual Colonies
PREPARING AN ANTIBACTERIAL LAWN FOR ANTIBIOTIC DISCS.
The lid/plug of the culture bottle/flask is held in the little finger. (never placed on the
bench) The bottle's neck is then passed through a Bunsen flame. (See Figure 3)
A pipette is partly removed from its packaging and a teat attached. 3-4 drops of a
liquid culture are removed from the culture and introduced into the petri dish. A
sterile spreader (cotton bud) is then used to spread the culture evenly over the agar.
An antibiotic disc is removed from its packet with sterile forceps and carefully
positioned on the agar surface using sterile forceps.
Similarly, other antiseptics or test solutions may be tested, by placing a small disc
of filter paper that has been dipped into a test solution onto the surface of the agar
spread with a bacterial lawn.
TAPING AND INCUBATION
Following inoculation, the petri dish base and lid should be taped together as shown
in Figure 6. Petri dishes should not be completely sealed as this may produce
anaerobic conditions and the selection of pathogens.
Fig 6. Taping petri dish lid after inoculation.
Plates should be labeled on their base with contents, date and student name. Ideally
this should occur prior to inoculation.
Plates should be incubated in an inverted position (that is agar side upwards) to
prevent condensation falling onto the colonies and contaminating them.
Plates should not be piled high otherwise they may fall spreading their contents
over the bench. Dish racks or baskets should be used or the plates taped together
with masking tape.
OBSERVATION OF PLATES
Petri dishes should generally be observed without opening the lid.
[Yr 11-12 may open the lids but only when necessary to subculture the bacteria or
for susceptibility testing, and only with samples of known “safe” bacteria, as per list in
appendix 1.] However a specific risk assessment must be completed and head of
Science approval sought for this process before attempting.]
SERIAL DILUTIONS
Use only the sterile disposable pipettes provided and dispose of into autoclavable
bag on tripod on bench. Do not place on bench after use.
MICROSCOPIC EXAMINATION OF BACTERIA. (Only to be attempted
after significant skill and competence achieved, and should be carried out in
Biological Safety Cabinet).
This procedure should only be carried out at Year 11 – 12 level when the students
have been taught and developed good aseptic techniques. A special risk
assessment would need to be completed and approval of the head science required
before attempting this technique.
Bacteria may be transferred to a microscope slide from an agar plate using a wire
loop or from a broth culture with a loop or pipette. If from an agar plate the
bacteria are mixed with the drop of sterile water, on the slide, using the loop. The
bacteria are spread into a very thin film using the end of another slide as for blood
smears. This film is then held high over a Bunsen flame to dry. It must not be
allowed to steam and hence produce aerosols.
If the smear is not dried within a few seconds it is too thick and the bacteria will
clump together and distort as they dry and fix onto the slide. All contaminated items
must be immediately placed in disinfectant. The fixed bacteria may then be stained
using a Gram staining technique.
A safer method of viewing bacteria on the microscope is to use yoghurt or Yakult
instead of the broth culture. This is suitable for Yr 8-12.
Other Practical Experiments
Other practical procedures (e.g. serial dilutions) may be attempted by senior biology
students, when students have developed good aseptic techniques. Standard
procedures for such procedures should be sourced, assessed, documented as a risk
assessment and followed carefully. Head of Science approval required.
Maintenance of Pure Bacteria Stocks
Broth cultures may be stored in the fridge for several weeks.
For short term storage petri dishes (or slopes) are preferred. When cultures are
maintained in the short term, a subculture should be plated out before starting a new
series of experiments and examined for signs of mixed growth, indicating that the
stock has been contaminated. Such contaminated broths should not be used.
The long-term storage of cultures in schools is not recommended and as such
will not occur at MBC.
DISPOSAL AND CLEAN-UP
General Clean-up
All contaminated items should be decontaminated prior to reuse or disposal.
Carefully organisation is required, to minimise re-handling and prevent the spread of
contamination. This can be achieved by lining special containers with autoclavable
bags for collection of items to be autoclaved. (NB: Glad oven bags make a good
substitute for autoclave bags).
Autoclavable bag in tripod frame on bench
All material waiting to be decontaminated must be held in a secure location away
from student areas or where it could be accidently disposed of by cleaners.
Glassware
Items for re-use should be immediately placed in disinfectant and soaked according
to the manufacturer's instructions, prior to washing. (e.g. 0.25% Sodium Hypochlorite
solution, soaked overnight)
Broth Cultures
Broth cultures should be sterilised by either autoclaving or addition of a suitable
disinfectant. (e.g. enough sodium hypochlorite to bring the culture to 1% available
chlorine solution, left overnight). Once sterilised it may be poured down the sink.
Petri Dishes.
When disposable petri dishes are no longer required they should be placed in an
autoclavable bag for sterilisation before disposal.
Once the bag is closed it should not be reopened to add additional plates as this
may produce high level of aerosols, and hence contamination.
A pressure cooker or microwave may also be used to disinfect petri dishes prior to
disposal. Only a laboratory microwave, not used for food, should be used. If none of
these methods is available, you must make arrangements with a licenced prescribed
waste removal company, for safe disposal. It is not permissible to discard petri
dishes into general or industrial garbage without prior sterilisation.
Incubator.
Following use the incubator must be thoroughly cleaned and disinfected
with an appropriate disinfectant. (eg. 0.1% available sodium hypochlorite or 70%
ethanol ).
Benches.
70% ethanol will be prepared and stored in a properly labelled spray bottle/s and
held in the preparation room.
Following each class using bacteria, the laboratory technician or teacher will spray
the benches with the 70% ethanol and wiped clear with paper towel.
Care must be taken by the person cleaning not to create aerosol of sodium
hypochlorite at the breathing zone.
The paper towels used for this may be disposed of in normal bin.
Correct Hand Washing Techniques
Facility.
Use only the hand basin with the sensor operated tap near the laboratory door.
Liquid soap dispensers will be used. Neutral pH, antibacterial soap will be used.
The dispenser must be cleaned and dried prior to refilling.
Washing technique.
Wet hands thoroughly and lather with antibacterial neutral pH soap, vigorously
rubbing hands together for at least 10-15 seconds.
Wash all parts of the hands, including back, wrists, between fingers and under
fingernails. Rinse well under running water.
Pat hands dry using disposable paper towel.
To minimise irritation and dryness a suitable hand cream may be used.
SPILLS
Students must be taught to report all spills to the teacher.
Only the teacher or laboratory technician shall clean up such spills.
If the spill is large or has caused a lot of splashing, aerosols ‘may’ have been
produced and the room should be evacuated for 30 minutes.
When cleaning spills disposable gloves must be worn.
Spill Kit - A spill kit should be prepared prior to starting microbiology practicals, and
be readily available. It should include all items required to clean up a spill, including
disinfectant, paper towel, gloves and plastic bags and containers for disposal.
Spills on the Body
The teacher must be informed immediately.
Contaminated clothing should be removed and the affected area washed vigorously
with soap and water. Medical attention may be sought if required. Any such incident
must be recorded as an accident / incident on the MBC form.
Contaminated clothing must be disinfected before washing.
Liquid Spills
Liquid spills should be covered with paper towel soaked in disinfectant (e.g. Sodium
Hypochlorite with 1 % available chlorine) for at least 20 minutes. The paper towel
should then be placed in a plastic bag for disposal. The area should be cleaned with
fresh paper towels soaked in disinfectant. Large spills may require the use of spillcontrol pillows or similar. These must be disinfected prior to disposal.
Contaminated Broken Glassware: Contaminated broken glassware should never
be picked up directly with the hands. It should be cleaned up using aids such as
brush and dustpan, forceps or cotton wool swabs.
Follow the procedure for liquid spills.
All aids used in clean-up must also be disinfected following use, using 1% sodium
hypochlorite.
FIRST AID
Cuts and Puncture Wounds from Contaminated Sharps.
Immediate first aid must limit contamination to the wound and to the first aider.
Any cut or puncture wound, caused by contaminated glass or sharps, must receive
immediate medical attention.
The student or staff member should go immediately to the Health Centre for
appropriate disinfection, and follow the nurse’s advice.
Existing skin wounds.
Minor cuts and abrasions which provide routes for infection from contaminated
surfaces should be adequately covered with water proof band aides, prior to
commencing any practical work.