2. Aseptic Techniques
A procedure performed under sterile condition
It is to prevent microbial contamination
It also protects the person who works on it from
infection
3. Aseptic Techniques in Microbial Work
Always sterilise the work bench with 70% ethanol
Prepare agar plates in laminar flow hood
Always wear gloves
All instruments for microbial work must be heat
sterilised or autoclaved before using
Work near a flame, as it creates a convection current
which prevents contaminants from settling on the
sample
4. Safety Precautions in
Microbial Work
Heat sterilise the inoculating loop with a flame until red
hot after using.
Dip disposable inoculating loop in 10% chlorox before
disposal.
Dispose all biohazard waste in the biohazard bag.
Autoclave all biohazard waste before disposal.
5. Autoclaving
It make use of a device known as autoclave to sterilise
apparatus or waste
It sterilises apparatus or waste using high pressure at
121oC for 15 - 20 minutes
Autoclave tape is normally pasted on the item to
indicate whether a specific temperature has been
reached
6. Autoclave Tape
It’s a tape similar to masking tape but it is more
adhesive and can withstand the hot and moist
conditions of the autoclave
The tape has diagonal markings that contains an ink
which changes colour from beige to black upon
heating
7. Biological Safety Cabinet
There are 3 classes of biological safety cabinet
Class I - Protect the person against contamination
from the sample.
Class II - Designed for use with low to moderate risk
biological agents and provide product, personnel, and
environmental protection.
Class III - Provide a physical barrier between biological
agents and personnel.
10. Air flow in Class II biological
safety cabinet
11. Laminar Flow Cabinet
This is often mistaken for a biosafety cabinet as they
look the same.
Laminar Flow cabinet only protect samples inside the
working area from external airborne contamination.
It does not protect user against contamination from the
sample.
Thus biohazardous activities (like bacteria work) should
never be carried out in it.
13. Use of micro-centrifuge
Tubes in the centrifuge must be balanced.
Dummy tubes or tubes filled with an appropriate
amount of water should be used if there is an odd
number of tubes needed to be centrifuge.
Micro-centrifuge should never be moved while in
operation
Never open a micro-centrifuge lid
while the rotor is moving.
14. Good Laboratory Practice
Petri dishes containing microbial cultures must be
labelled with the following before incubating :
Name of the micro-organism / sample
Date of start of culture
Date of completion of culture
Name of student and teacher in charge
15. Dealing with minor micro-
organism spillage
Always report a spillage to the teacher or technician
before cleaning up yourself.
For minor spillage, cover the spill area with a piece of
tissue and poured disinfectant (like Dettol or bleach
solution) over it and left it to stand for at least 30
minutes.
Wear gloves and dispose the stained tissue into
biohazard bag for autoclaving.
16. Dealing with major micro-
organism spillage
Report the spillage to the teacher or lab technician.
Teacher or lab technician will assess the severity of the
spillage and if necessary all personnel in the room
should leave the laboratory immediately.
Cleaning of the spillage will be done by lab technician
with proper protective clothing.
17. Dealing with specific accidents
involving micro-organisms
Injection, cuts & abrasions - Remove clothing of the
affected part. Gently squeeze the wound to encourage
slight bleeding. Wash the affected part and apply
appropriate antiseptic.
Ingestion of micro-organisms - Rinse the mouth
and drink several glasses of water and induce vomiting.
This can be done by stimulating the back of the throat
with the tip of a finger.
18. Dealing with specific accidents
involving micro-organisms
Micro-organism in contact with skin - Remove any
contaminated clothing. Washed affected area with soap and
water. Apply antiseptic if micro-organism is in contact with
broken skin.
Micro-organism in contact with eyes - Flush the eyes with
running water using the eye washers for a minimum of 15
minutes.
Always consult a doctor immediately and inform the
doctor of the nature of the wound and micro-organism
after applying the first aid as mentioned above.
19. Chemicals
Chemical can be classified into the following table with
its corresponding effect.
Classification Effects
Flammable properties even when not in contact
Oxidising with other combustible material
Flammable Low Flash Point
Corrosive Can cause skin burns
Irritant Can cause significant skin inflammation
Mutagenic Can cause heritable genetic damage
Carcinogenic Can cause cancer
20. Dealing with chemical
spillage
Report to teacher or lab technician when spillage
occurs.
Wear gloves if the chemical is hazardous.
Use tissue to soak up the spillage followed by wiping
the area with a damp tissue.
Mercury spillage will be handled by the lab technician,
do not clear up mercury spillage by yourself.
21. Dealing with accidents
involving chemicals
First aid administrated is the same as dealing
with accident in contact with micro-organism.
Chemical burns - Remove any clothing or shoes that
is contacted with the chemical. Wash the injured area
with cool running water for at least 10 minutes.
If possible, soak the injured area in cold water to numb
the wound. Do not apply any burn ointment to affected
area. Dry the wound and cover with a sterile gauze.
22. Electrical Injury
Switch off the supply affecting the casualty and remove
the person from contact with the apparatus.
Inform the teacher or lab technician to call ambulance
by dialling 995 if they access it as a serious situation.
If there is a trained personnel, do artificial resuscitation
and cardiac massage immediately.
23. Cuts and bleeding
Minor case - Remove dirt or glass, wash under
running water and apply clean, dry, sterile dressing (like
plaster)
Serious case - Let the casualty lie down. Remove dirt
or glass by washing under running water. Apply
pressure to the wound with a thick pad of gauze and a
firm bandage. Call 995 for ambulance.
In any case of emergency, please inform the
teacher or lab technician before applying the first
aid to the casualty.