Laboratory practicals in microbiology deal with experimentations and research, isolation and identification
of the various microbes and parasites that may be present in collected samples and/or specimens.
Knowledge and theory in biology originated from practical observation and experiment. Even when theoretical principles have been well
taught, the practical aspects of microbiology should neither be ignored nor compromised. Students should therefore be encouraged to take part in practical demonstrations and
exercises especially as practical sessions form an important part of most of the courses in microbiology.
Practical skills and knowledge in methods in microbiology are acquired and developed in the laboratory. The laboratory techniques, abilities and skills acquired and developed in practical
classes, will continue to be useful to the student throughout his course and beyond.
The principles and techniques employed in various
laboratory methods in microbiology and immunology are
well outlined in the relevant chapters and sections.
Discussions were centered on principle, theory, equipment as well as application of the techniques. Special attention has
been given to the basic techniques which are essential in the teaching of microbiology and techniques used routinely in Microbiological assays. Some of these techniques can be adapted for biochemical tests and investigations.
Laboratory work/studies involving isolation and
characterization of microorganisms based on their gram
reaction, cultural characteristics, physiological (biochemical) and serological reactions form the identification and classification.
While working with microorganisms, some of which maybe pathogenic, the individual is exposed to many
annually in many microbiological establishments and among laboratory workers.
Fortunately, some of these
infections- and hazards are preventable. It is important therefore to properly and regularly educate the student and
new laboratory staff on the potential hazards of the materials and organisms they will come in contact with and
For example, many students and laboratory workers in our
the routes by which these organisms enter the human body.
Environment do not know that splashes of infected material
into the eyes and transfer of organisms on contaminated fingers to different parts of the body including the eyes are
very common routes of infection. Neither do they know that
hazards. Laboratory acquired infections are on the increase inhalation of aerosols containing microorganisms which are
and syringes, pipettes, culture tubes and dishes is frequently released during microbiological work with loops
infections.
ESTABLISHMENT OF A MICROBIOLOGY LABORATORY
Setting up a Microbiology laboratory is a special art and task which requires some basic equipment and space
which will make the Laboratory functional and effective.
Every Microbiology Laboratory must meet the minimum standards required by International Committee of
Microbiological Society (1CMS) and Nigeria Universities Commission (NUC). Other standards like Ministry of
Science, NAFDAC, Medical Laboratory Science Council of Nigeria (MLSCN), Standards Organization of Nigeria (SON)
and Nigeria Society for Microbiology (NSM) must equally be met.
One of the most important requirements for a Microbiology Laboratory is accommodation and space.
Laboratories require large spaces due to the number and size of equipments that are needed. Some of these equipments
are required to be kept in ventilated, well-lit places while
others requires less ventilated and dark places.
Theaccommodation must be spacious in order to allow for free
movement and passage of people and materials inside the Laboratory. Unimpeded movement aids quick transfer, measurement and other analytical procedures that are
normally carried out in the Laboratory.
Accommodations with very good ventilation allows for free diffusion of
chemicals, gases and dispersant in the air around the Laboratory. Work benches, sinks, pumps, electricity – sockets and plugs, cupboards and storage facilities must be provided.
The floors of every laboratory should be smooth, it should not be slippery nor dusty. The work benches should
be made with Formica or white tiles. Fans should not be fixed near serious aseptic Microbiological activity sites.
Rather than fans, air – conditioners are preferable especially if it has air filter units. All the work tops should have outlets for gas, water and any other gas or chemicals required for routine analysis.
Water is the most important utility required in any Microbiology Laboratory. Water is required for washing, as a solvent and for various analytical procedures.
The general questions that must be put into consideration before setting up a Microbiology Laboratory
include the following:
1. Is there a person trained to perform the required tests and experiments?
2. Can the necessary measures be taken to ensure the safe collection, transport, processing and disposal of specimens?
3. Is it possible to organize a reliable system for supplying the laboratory with reagents and other essential supplies?
4. Is the cost of managing the laboratory affordable, including the cost of supplies, maintaining equipment and staff salaries? How will laboratory expenditures be met?
5. Can a room be provided that is:
- Structurally sound with secure door(s), and burglary proof, insect-screened windows that provide adequate light and ventilation.
- Sufficiently large to be sub-divided into areas for working, reception of visitors and specimens, keeping records, decontamination
of infected material and cleaning of laboratory ware. - Provided with running water.
- Provided with separate sinks for cleaning laboratory wares and hand washing.
- Fitted with facilities for the safe disposal of specimens.
- Wired for mains electricity or if unavailable supplied with an alternative source of power,
e.g battery, rechargeable from a solar panel or generator. - Fitted with appropriate washable working surfaces, seating for students and staff, secure
storage cupboards, and shelving.
6. Is it possible to provide all the important instruments that are essential to research?
The Laboratory must work towards overcoming some problems that may lead to poor performance which include:
- using inappropriate technologies.
- equipment that is not sufficiently rugged.
- reagents that have deteriorated due to heat, high relative humidity or incorrect storage.
- bypassing quality control procedures because
they are too time – consuming or difficult to apply. - Use of unskilled personnel.
Every Microbiology Laboratory should also have an inbuilt method that will aim towards in-service and skill acquisition training that will enable the Laboratory to always meet up with expectations such as meeting up with problems of improvising and that of building total quality management of the Laboratory.
For every Microbiology Laboratory there must be a laid down standard operating procedure (SOPS). This usually help the staff in the Laboratories to follows set of
rules and guidelines that propel the Microbiology Laboratory to excellency and accuracy in its methods of
operation.
LABORATORY RULES IN MICROBIOLOGY
In view of the potential hazards of the materials and organisms handled by laboratory workers in a microbiology
Laboratory, efforts must be made to create awareness among laboratory users (especially students) of the routes by which pathogenic microorganisms
can enter the human body and
cause infections.
Also effort must be made to properly instruct all laboratory workers to avoid unnecessary exposure to microorganisms. Insistence on constant practice of good microbiology techniques is essential to avoid infection and ensure safety.
The following code of practice should be strictly adhered to:
1. All Laboratory users should wear clean white Laboratory coats during practical work in order to protect clothing against possible contamination. Laboratory protective clothing should be removed when the worker leaves the Laboratory.
2. Every precaution should be taken in handling culture to prevent their dispersal into the laboratory.
3. Should any culture be spilt or broken, the worker must not attempt to clean his bench or the floor without first informing the persons in charge of the
practical class.
4. Benches should be swabbed with disinfectant before starting a class, or work.
5. All body fluids and pathological materials should beregarded as potentially infectious. This is the
universal precaution.
6. Discard culture or infected material (pus, blood, sputum) must be placed in discard tins provided for this purpose, and should not leave the laboratory
until it has been sterilized.
7. Mouth pipetting should be banned and pipetting devices provided.
8. The use of hypodermic needles should be restricted.
9. Do not place any object on the laboratory bench which may be transferred to the mouth consciously or
unconsciously. This includes cigarettes and other smoking materials, pencils, labels, pipes, mouthpieces of rubber tubing attached to pipettes, handkerchief, stamp, books, cotton wool plugs.
10. Avoid talking or coughing during subculturing.
11. Bacteriological loops should be completely closed with a diameter not more than 3mm and held in
metal and not glass handles.
12. At the end of each practical work, benches and work surfaces should be disinfected.
13. Food should not be brought into the laboratory.
14. Sharp glass Pasteur pipettes should_ be replaced by soft plastic varieties; Cracked and chipped glassware should be replaced.
15. Discard jars for small objects and for re-usable pipettes should beprovided in the laboratory. Discard bins or bags should be placed near to. each lab and should be properly disposed off at the end of each working day.
16. Hands should be washed after handling infectious materials and always before leaving the laboratory.
17. Whenever (a student is) in doubt as to laboratory procedure, seek the advice of the demonstrators.
18.Do not begin any exercises until the directions have been read and understood.
19. All observations should be properly recorded in a laboratory note book.