Ella McKnight
Unit 17
Learning aims C & D
Culturing microorganisms
Ensuring safety and the prevention of contamination is vital when working in microbial
culturing. Microbial cultures are made for many different reasons such as research,
industrial applications. In each of these different settings they all have one thing in common,
it needs to be a sterile environment. A sterile environment helps the microorganism to
thrive and also yield accurate results. Accurate results are important as if not correct it can
lead to misleading results, if there is contamination the results produced are not right, the
experiment is compromised, and different substances can react with each other so in worst
case scenarios hazardous situations can occur.
To prevent contamination within the microbiological laboratories there are certain
protocols and procedures in place to help ensure samples and specimens are not
contaminated. There are 4 different classifications of biosafety, levels 1 through to 4. These
are a set of containment precautions that are used to isolate dangerous biological agents,
biological agents are the different microorganisms in laboratories.
Risk level 1- In a risk level 1 lab, there is low risk to all individuals and a low risk to
communities. Work is done on an open bench, although there is low risk to all individuals
PPE should still be worn; PPE is equipment such as lab coats, gloves and goggles. The
exposure levels are low within level 1 labs, but it is still essential to main good cleanliness
and organisation, it is also vital to dispose of chemical waste correctly, this is to help prevent
unnecessary cross-contamination. All potentially infectious material has to be
decontaminated before disposal, this is done with an autoclave. Some of the
microorganisms we can work with in a level 1 lab include Staphylococcus albus,
Saccharomyces cerevisiae, non-pathogenic E. coli. These labs are mainly found in schools
and colleges, when carrying out my practicals with Escherichia coli I worked in a Risk 1 lab.
Hand washing is essential when entering or exiting the lab, this helping to prevent
contamination and keeping a sterile environment. No eating or drinking within the lab as
well, this helps to prevent the risk of consumption or contamination with skin.
Risk level 2- In a risk level 2 lab, there is a moderate risk to all individuals and low risk to
communities. This is due to the fact the microorganisms being used are typically associated
with human diseases that are sometimes serious, this includes Salmonella SPP,
Staphylococcus aureus, Hepatitis B and C. When working with these microorganisms there
are more precautions that need to be put in place, all the precautions from a risk 1 lab are
still abided. Training for handling pathogens agents is required and when using you must
have supervision from a competent senior qualified scientist, unlike a risk 1 lab there is
limited access to the lab whilst work is in progress. This is done by access control which only
allows authorised personnel to enter the lab. When working with certain microorganisms in
a risk 2 lab, biological safety cabinets are used, this helps to prevent exposure to the
infectious agent. Risk level 2 laboratories are used mainly within research labs and also in
pathology. This is similar to the lab I worked in, although there are more precautionary
measurements put in place such as the access control and the training required to work
with the microorganisms.
, Ella McKnight
Unit 17
Risk level 3- In a risk level 3 lab, there is a high risk to individuals and a moderate risk to
communities. These labs are designed for working with microorganisms that can cause
serious of potentially lethal diseases through skin contamination, digestion or inhalation.
These infectious agents are normally indigenous or exotic such as Mycobacterium
tuberculous, Yersinia pestis, SARS and rabies. Within a level 3 lab all precautions from level 1
and 2 are still in place, there is more enhanced PPE in place in addition to the basics of lab
coats, goggles and gloves when working in a level 3 lab respiratory protection is required,
this is done by the use of N95 respirators or powered air-purifying respirators. You may also
be required to remove all jewellery and makeup. These labs also have controlled access, but
it is stricter than it would be in a level 2. Limited entry to different places, have to be
authorised personnel only. Training is also more intensive; it has to be specific and given to
all personnel who come in contact with the pathogens. All procedures involving level 3
microorganisms have to be completed in a containment cabinet, either a class 2 or 3. These
labs are also fitted with specialised ventilation, this provides directional airflow and HEPA
filters (removes at least 99.97% of dust, bacteria and any airborne particle within a size of
0.3µm.) This ensures the air within these labs is filtered before being released back into the
environment. All surfaces and equipment used within these labs has to be decontaminated
and all materials that could contain traces of the pathogen either get autoclaved or
incinerated. Risk level 3 labs are normally used within Pathology and also research labs.
Compared to the lab I worked this has a lot more measures in place due to the higher
severity of microorganisms being worked on, the higher levels of controlled access. Much
more advance PPE being used, along with purifying air systems with HEPA filters. Intensive
training required to work with these pathogens.
Risk level 4- In a risk level 4 lab, there is a high risk to individuals and a high risk to
communities. These labs are designed for working with microorganisms at the highest level
of containment, these labs work with extremely hazardous pathogens that pose a high
threatening risk of life-threatening disease, which has no vaccine or treatment.
Microorganisms that would require a level 4 biosafety lab would include Ebola virus,
smallpox, Herpes B virus, Marburg virus. When working with these pathogens within a level
4 lab all precautions from the 3 previous levels is still in place, but there are more
precautions in place. The lab is physically separated from other areas, it has high levels of
security so no unauthorised personnel can enter. PPE is even more extensive in level 4 labs,
personnel working with the infectious agent must wear a positive-pressure suit with its own
supply of oxygen, this helping to protect against airborne pathogens. May also be required
to shower upon entering and leaving the lab and the containment suits must be put on
before stepping into the lab as wearing your own clothes is not allowed. Level 4 labs like
level 3 have specialised ventilation systems, within a level 4 lab there is a double door entry
with an airlock unlike level 3, but the ventilation system is somewhat the same as level 3
with the HEPA filtration, but it is also kept at a negative pressure to ensure any air released
is filtered. Training for working in a level 4 lab is a lot more extensive than it would be in any
of the 3 previous due to how hazardous the pathogen is that is being worked with. These
microorganisms are worked with in advanced biological safety cabinets, a class 3 safety
cabinet is used. This is where the scientist manipulates the cultures of pathogens by putting
their hands inside special gloves in a gas-tight cabinet, this allows it to be worked on without
any direct exposure. In level 4 labs decontamination is rigorous, all materials and surfaces
Unit 17
Learning aims C & D
Culturing microorganisms
Ensuring safety and the prevention of contamination is vital when working in microbial
culturing. Microbial cultures are made for many different reasons such as research,
industrial applications. In each of these different settings they all have one thing in common,
it needs to be a sterile environment. A sterile environment helps the microorganism to
thrive and also yield accurate results. Accurate results are important as if not correct it can
lead to misleading results, if there is contamination the results produced are not right, the
experiment is compromised, and different substances can react with each other so in worst
case scenarios hazardous situations can occur.
To prevent contamination within the microbiological laboratories there are certain
protocols and procedures in place to help ensure samples and specimens are not
contaminated. There are 4 different classifications of biosafety, levels 1 through to 4. These
are a set of containment precautions that are used to isolate dangerous biological agents,
biological agents are the different microorganisms in laboratories.
Risk level 1- In a risk level 1 lab, there is low risk to all individuals and a low risk to
communities. Work is done on an open bench, although there is low risk to all individuals
PPE should still be worn; PPE is equipment such as lab coats, gloves and goggles. The
exposure levels are low within level 1 labs, but it is still essential to main good cleanliness
and organisation, it is also vital to dispose of chemical waste correctly, this is to help prevent
unnecessary cross-contamination. All potentially infectious material has to be
decontaminated before disposal, this is done with an autoclave. Some of the
microorganisms we can work with in a level 1 lab include Staphylococcus albus,
Saccharomyces cerevisiae, non-pathogenic E. coli. These labs are mainly found in schools
and colleges, when carrying out my practicals with Escherichia coli I worked in a Risk 1 lab.
Hand washing is essential when entering or exiting the lab, this helping to prevent
contamination and keeping a sterile environment. No eating or drinking within the lab as
well, this helps to prevent the risk of consumption or contamination with skin.
Risk level 2- In a risk level 2 lab, there is a moderate risk to all individuals and low risk to
communities. This is due to the fact the microorganisms being used are typically associated
with human diseases that are sometimes serious, this includes Salmonella SPP,
Staphylococcus aureus, Hepatitis B and C. When working with these microorganisms there
are more precautions that need to be put in place, all the precautions from a risk 1 lab are
still abided. Training for handling pathogens agents is required and when using you must
have supervision from a competent senior qualified scientist, unlike a risk 1 lab there is
limited access to the lab whilst work is in progress. This is done by access control which only
allows authorised personnel to enter the lab. When working with certain microorganisms in
a risk 2 lab, biological safety cabinets are used, this helps to prevent exposure to the
infectious agent. Risk level 2 laboratories are used mainly within research labs and also in
pathology. This is similar to the lab I worked in, although there are more precautionary
measurements put in place such as the access control and the training required to work
with the microorganisms.
, Ella McKnight
Unit 17
Risk level 3- In a risk level 3 lab, there is a high risk to individuals and a moderate risk to
communities. These labs are designed for working with microorganisms that can cause
serious of potentially lethal diseases through skin contamination, digestion or inhalation.
These infectious agents are normally indigenous or exotic such as Mycobacterium
tuberculous, Yersinia pestis, SARS and rabies. Within a level 3 lab all precautions from level 1
and 2 are still in place, there is more enhanced PPE in place in addition to the basics of lab
coats, goggles and gloves when working in a level 3 lab respiratory protection is required,
this is done by the use of N95 respirators or powered air-purifying respirators. You may also
be required to remove all jewellery and makeup. These labs also have controlled access, but
it is stricter than it would be in a level 2. Limited entry to different places, have to be
authorised personnel only. Training is also more intensive; it has to be specific and given to
all personnel who come in contact with the pathogens. All procedures involving level 3
microorganisms have to be completed in a containment cabinet, either a class 2 or 3. These
labs are also fitted with specialised ventilation, this provides directional airflow and HEPA
filters (removes at least 99.97% of dust, bacteria and any airborne particle within a size of
0.3µm.) This ensures the air within these labs is filtered before being released back into the
environment. All surfaces and equipment used within these labs has to be decontaminated
and all materials that could contain traces of the pathogen either get autoclaved or
incinerated. Risk level 3 labs are normally used within Pathology and also research labs.
Compared to the lab I worked this has a lot more measures in place due to the higher
severity of microorganisms being worked on, the higher levels of controlled access. Much
more advance PPE being used, along with purifying air systems with HEPA filters. Intensive
training required to work with these pathogens.
Risk level 4- In a risk level 4 lab, there is a high risk to individuals and a high risk to
communities. These labs are designed for working with microorganisms at the highest level
of containment, these labs work with extremely hazardous pathogens that pose a high
threatening risk of life-threatening disease, which has no vaccine or treatment.
Microorganisms that would require a level 4 biosafety lab would include Ebola virus,
smallpox, Herpes B virus, Marburg virus. When working with these pathogens within a level
4 lab all precautions from the 3 previous levels is still in place, but there are more
precautions in place. The lab is physically separated from other areas, it has high levels of
security so no unauthorised personnel can enter. PPE is even more extensive in level 4 labs,
personnel working with the infectious agent must wear a positive-pressure suit with its own
supply of oxygen, this helping to protect against airborne pathogens. May also be required
to shower upon entering and leaving the lab and the containment suits must be put on
before stepping into the lab as wearing your own clothes is not allowed. Level 4 labs like
level 3 have specialised ventilation systems, within a level 4 lab there is a double door entry
with an airlock unlike level 3, but the ventilation system is somewhat the same as level 3
with the HEPA filtration, but it is also kept at a negative pressure to ensure any air released
is filtered. Training for working in a level 4 lab is a lot more extensive than it would be in any
of the 3 previous due to how hazardous the pathogen is that is being worked with. These
microorganisms are worked with in advanced biological safety cabinets, a class 3 safety
cabinet is used. This is where the scientist manipulates the cultures of pathogens by putting
their hands inside special gloves in a gas-tight cabinet, this allows it to be worked on without
any direct exposure. In level 4 labs decontamination is rigorous, all materials and surfaces
