This document discusses the maintenance and proper use of various laboratory equipment, including: 1) A biosafety cabinet which is used to work under sterile conditions and must be cleaned regularly with alcohol and have UV light switched on for sterilization. 2) An incubator which maintains the proper temperature for culturing samples and is cleaned weekly on the inside with alcohol. 3) A refrigerator which stores samples and reagents below 8°C and is cleaned regularly on the inside and outside. 4) A deep freeze which stores items below -20°C and is monitored daily for temperature and cleaned monthly.

1. EQUIPMENT
MAINTENANCE
Dr. Hemali Parmar
MBBS, M.D. Microbiology
Tutor, Baroda Medical College, Gujarat

2. Equipments used in laboratory
 Biosafety cabinet
 Incubator
 Refrigerator
 Deep freeze
 Hot air oven
 Centrifuge
 Microscope
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3. Biosafety cabinet
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4. Biosafety cabinet
 This instrument is used to work for Sample
Inoculation, Antibiotic Sensitivity Testing and Smear
Preparation under sterile environment
START UP:
 The inner surface (both horizontal & vertical) of
cabinet is cleaned & disinfected with 70% Alcohol
solution. Then, the shutter is closed.
 The U.V. light is switched on for ½ hr.
 The airflow is switched on for 10 min. before starting
the work.
 The U.V. light is switched off and the simple light is
switched on before starting the work.
 Then the shutter is opened.
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5. contd…
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Procedure
 All materials & equipments required to carry out the work are
collected & checked before starting the work. :
 The discarding beaker containing freshly prepared 1% Sod.
Hypochlorite with lid is placed inside BSC before starting the work.
 Only necessary items that are required for the laboratory work to be
carried out are kept inside the cabinet, & no material is kept on the
air holes, so that airflow of the BSC Class - II is not obstructed.
 It is checked that the front & the back grills are not blocked at any
time during the work.
 Gloves, masks & cap are worn before starting the work.
 While working in the cabinet, the used material is discarded in the
discarding beaker containing 1% Sod. Hypochlorite.
 The discarding container is covered properly with aluminum foil &
then autoclaved.
 The cabinet is cleaned with 70% alcohol solution after every
working session.

6. Contd…
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SHUT DOWN:
 The inner surface of the cabinet is cleaned
and decontaminated with alcohol or spirit
solution.
 The shutter is then closed.
 The simple light & airflow are switched off.
 U.V. light is switched on for 10min.
 The U.V. (Ultraviolet) light is then switched off.

7. MAINTENANCE SCHEDULE
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 Proper cleaning of BSC is done regularly
before starting the work and completing the
work.
 Direct exposure to U.V. light is avoided.
 All precautions are taken to avoid cross
contamination while working in the hood.
 Toxic, explosive or flammable substances are
not used in this cabinet.
 The sterility is checked every fortnightly using
BHI/ NA agar plates.

8. Incubator
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9. Incubator
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 This instrument is designed to create stable,
reliable environment for incubation of
inoculated culture plates and biochemical
tests.
PROCEDURE:
 For the first time, switch on the mains supply
and allow it to warm up to the required
temperature i.e. 370C.
 Monitor the incubator for temperature stability
for 24 hours.
 Now keep the plate/ rack inside incubator.

10. MAINTENANCE
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 Place the equipment on flat surface away from direct sunlight.
 Clean exterior of incubator daily with a clean wet mop.
 Clean the interior of the incubator once a week using sterile cotton
or gauze soaked in 70% Alcohol or 0.1% Sodium hypochlorite
solution. Allow the interior to dry completely.
 Temperature of the incubator is to be recorded daily with a
calibrated thermometer. Temperature chart should be maintained.
Record the temperature of incubator in the morning in the
temperature-monitoring sheet on the incubator by the first person
who opens it.
 At the end of month the temperature record sheet is filed in File No
D-21 Temperature record file.
 Any operating problem should be recorded and to be brought in
notice of the Section officer concerned.
 Service person should be informed regarding the problem as soon
as possible to solve the problem.

11. Refrigerator
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12. Refrigerator
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 It is used to store samples, Antibiotic sensitivity discs and culture
plates in follow up & reagents.
Maintenance
 Place the equipment on flat surface away from direct
sunlight.
 Refrigerator must be placed in such place where sufficient
air can circulate to facilitate heat exchange of compressor.
 Always close the refrigerator door to prevent warm air from
outside to enter cool chamber.
 Do not store eatables in refrigerator.
 Record the temperature of refrigerator in the morning in the
temperature-monitoring sheet on the refrigerator, by the
first person who opens it. Similarly record the temperature
of refrigerator in the evening.
 Temperature should not exceed 08°C.

13. Contd…
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 Clean the cool chamber with freshly prepared 70% alcohol/
0.1% Sodium hypochlorite once every fortnightly and wipe
with sterile cloth after defrosting properly.
 Clean refrigerator from outside daily with a clean wet mop.
 Keep the compressor dust free.
 Clean door gasket.
 Record the temperature and cleaning in File No D-21
SAFETY CONDITION:
 Check for leakage or exhaust of gas and if found inform the Section
in-charge and workshop immediately.
 For any problem in the refrigerator the officer in- charge must be
informed immediately.
 Service person should be informed regarding the problem as soon
as possible to solve the problem.

14. Deep freeze
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15. Deep freeze
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 Deep freeze is used to store Antibiotic discs &
sometimes stock culture.
 Operation:
 The Deep freeze is switched on.
 Adjustment of the required temperature i.e. -
20C is done.
 After the required temperature is attained, the
necessary materials are put inside the deep
freeze.

16. Contd…
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Maintenance:
 Temperature of the deep freeze is daily recorded in the
morning in the temperature monitoring sheet which is pasted
on the incubator. Temperature should not exceed 20 0C.
 One temperature sheet includes charts for 1 month
temperature record. At the end of 1 month, the temperature
record sheet is filed in File No.-BF6 ‘Temperature monitoring
file’.
 Defrosting is done once a month. The cool chamber is
cleaned with 70% Alcohol and wiped with clean cloth after
defrosting properly. While defrosting, contents are kept in
freezer compartments of refrigerator No.1 & 2.
 The deep freeze is cleaned from outside (at least once a
month).

17. Contd…
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Safety precautions:
 Disconnect unit from main power before attempting
any maintenance to equipment or control.
 Do not keep the door opened for longer period of
time.
 Check for leakage or exhaust of gas and if found
inform the Section in charge and workshop
immediately.
 Do not use metal or sharp scrapers to scrape off
frost.
 Do not open the lid of the freezer unnecessarily or
frequently.
 Any operating problem should be recorded and to
be brought in notice of the laboratory In-charge.

18. Hot air oven
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19. Hot air oven
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 This instrument is designed to sterilize the test
tubes, or to dry the media plates before
inoculation.
Procedure:
 Switch on the mains supply and allow it to
warm up to the required temperature.
 Start using the hot air oven after the
temperature has reached the required
temperature.
 Keep the plates/ rack inside incubator after the
temperature has reached the required
temperature and is maintained for 30 minutes.

20. Contd…
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Maintenance:
 Place the equipment on flat surface away from direct sunlight.
 Clean exterior of hot air oven daily.
 Clean the interior of the instrument once a week using sterile
cotton or gauze soaked in 70% Alcohol or 1% Sodium
hypochlorite solution. Allow the interior to dry completely.
 Temperature of the instrument is to be recorded daily,
whenever put in use, with a calibrated thermometer.
Temperature chart should be maintained.
 At the end of month the temperature record sheet is filed in
File No D-21
 Any operating problem should be recorded and to be brought
in notice of the Section officer concerned.
 Service person should be informed regarding the problem as
soon as possible to solve the problem.

21. Centrifuge
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22. Centrifuge
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 This is used for centrifugation of body fluids except for sputum.
Procedure:
 It should be placed on flat and non slippery surface, to prevent
moving away from place when in use.
 Its load should be balanced always, for balance dummy tube filled
with equal quantity water can be placed on opposite side.
 Cover it with lid before using it.
 Turn speed control slowly up and down.
Maintenance:
 Switch off immediately if makes abnormal noise.
 After use invert buckets to drain dry.
 After any spillage, wipe and disinfect immediately with freshly
prepared (within 8 hrs.) 0.5% Sodium hypochlorite.
 Clean it daily.
 Check for brushes and bearing every 3 monthly.

23. Contd…
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Safety precautions:
 Do not use without balance on opposite side
 Do not stop it manually.
 Do not use without plugging the test tube mouth.
 Speed should not be raised rapidly.
 Switch off immediately if there is breakage of
tube.
 For any problem in the centrifuge the officer in-
charge must be informed immediately.
 Service person should be informed regarding the
problem as soon as possible to solve the problem.

24. Microscope
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25. Microscope
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 This instrument is designed to visualize the
microorganisms that one can not see with naked eye
in different clinical samples as well as slides prepared
from culture positive colonies.
Procedure:
 Switch on the mains supply and then switch on the
supply from base of the microscope.
 Adjust the objective and condenser as per
requirement and place the slide on the stage.
 Make coarse and fine adjustment to focus the slide.
 After the work is over switch off the electric supply first
on base and then from the mains.

26. Contd…
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Maintenance:
 Place the equipment on flat surface away from direct
sunlight.
 Keep the Microscope covered when not in use.
 Clean the objective lens with soft cotton cloth or tissue
paper after use.
 Do not clean the lens with alcohol or xylene as it may
damage the cement.
 Any operating problem should be recorded and to be
brought in notice of the Section officer concerned.
 Service person should be informed regarding the
problem as soon as possible to solve the problem.