Ohio Water Microbiology Lab
Research Topics
Internal Information
Ohio Water Science Center
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OWML: QA/QC
Quality Assurance/Quality Control Manual: Ohio Water Microbiology
Laboratory
Microscope
There
are two Zeiss microscopes used to perform microscopy. The Zeiss Axio Imager
microscope has the capability to perform fluorescence microscopy and
differential interference contrast (DIC). Additionally, it is equipped with a
digital camera. This microscope is used for specialized laboratory work and for
enumerating Cryptosporidium oocysts and Giardia cysts by USEPA Method 1623. The
microscope has three objectives: 20X, 40X and 100X (oil), as well as an ocular
micrometer. Furthermore, the microscope is equipped with excitation/band-pass
filters for the immunofluorescence assay (FA) and 4’, 6-diamidino-2-pheylindole
(DAPI) analysis. The microscope also has optics for DIC analysis under the 100X
objective. It is kept in a room capable of being almost completely darkened.
The older Zeiss microscope is used for general laboratory work, Gram Stains, and
Actinomycetes analysis. It is equipped for fluorescence microscopy, so it can
also be used to enumerate Cryptosporidium oocysts and Giardia cysts, if
necessary. It has five objectives: 10X, 25X, 40X, 63X and 100X (oil), as well as
an ocular micrometer.
- The
mercury bulb power supply for the Zeiss Axio Imager has an automated timer
to monitor the number of hours the bulb has been on. After 150-200 hours,
the mercury bulb should be changed. Note: the maximum life expectancy of the
bulb is 300 hours. Call the manufacturer’s local representative or a
professional company for assistance. The bulb must be disposed of in
accordance with legal regulations, not in domestic waste. Contact the Carl
Zeiss microscopy service for assistance. Record the mercury bulb number and
date of installation in the LIMS.
- The
mercury bulb power supply for the older Zeiss microscope has a log book to
record the number of hours the bulb has been in use. As explained above, the
bulb should be changed after 150-200 hours and the appropriate information
recorded in the LIMS.
- The
ocular micrometer is calibrated for each objective at the time of purchase
of the microscope by the manufacturer’s local representative. If a new
objective is purchased for the microscope, the micrometer will need to be
calibrated for this objective.
The cleaning procedures are the same for both microscopes.
- The
microscope is cleaned by a professional company yearly. Record this
maintenance in the LIMS.
- After
each use, clean the objectives and stage with lens paper and lens cleaner. A
Q-tip and lens cleaner can be used to help remove oil from the end of the
objective, as well as keep the oculars clean. Keep the dust protection cover
on the microscopes while not in use and let the lamp housing cool before
putting on the cover.
- As
needed, blow dust off of the microscope (especially the condenser, field
aperature, and the oculars) with compressed air.
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