OWML: QA/QC

Quality Assurance/Quality Control Manual: Ohio Water Microbiology Laboratory

Thermometers, incubators, water baths, refrigerators, and freezers
Thermometers are kept in three areas and are inventoried according to storage and use: (1) the National Institute of Standards and Technology (NIST) thermometer (2) daily-use water-bath, incubator, and refrigerator thermometers, (3) digital thermometers, and (4) back-lab thermometers.

• The NIST thermometer is calibrated and certified annually by an outside service technician. Certification dates are recorded in the LIMS. Calibration records are stored in the equipment logbook.
   
• Daily-use and back-lab thermometers are checked quarterly against the NIST thermometer. Results are recorded in the LIMS and acceptance criteria are listed in table 4. Criteria are based on use.
   
• Digital thermometers are checked quarterly against the NIST thermometer and are calibrated annually by the manufacturer. Results and calibration dates are recorded in the LIMS.

There are 7 incubators, 6 water baths, 5 refrigerators and 5 freezers in use in the laboratory. Temperature settings and criteria for acceptance are dependent on use (table 3). Approximately 11 aluminum-block blue field incubators and 2 double-chamber gray incubators are used for laboratory and field operations.

• The temperatures of the laboratory incubators, water baths, and refrigerators are checked monthly with NIST-calibrated laboratory thermometers and recorded in the LIMS. During use, the incubators, water baths, and refrigerators are checked daily and recorded on a designated daily log sheet posted in the front or on a side of each piece of equipment. Temperature daily log sheets are stored in the Temperature logbook.
   
• The temperatures of the freezers are checked quarterly with NIST-calibrated laboratory thermometers and recorded in the LIMS. The -70ºC freezers are equipped with automatic alarms that are set to respond when temperatures rise above -60ºC; the alarm system sounds during regular working hours and is attached to a telephone notification system after hours.
   
• The operating temperatures of microbiological aluminum-block incubators are checked annually (or in preparation for a major study) and recorded in the LIMS. During periods of heavy use in the laboratory or in the field, the temperatures are checked and recorded daily.
   
• The two –70oC freezers (freezers 3 and 4) are used to store samples and microbiological cultures. A filter is cleaned and fans behind the filter are checked by laboratory personnel for operation quarterly and dates are recorded in the LIMS. The condenser is dusted or vacuumed every 6 months and recorded in the LIMS. A temperature chart is changed after a single pass around the chart (weekly).
   
• Water baths are filled with distilled water and are cleaned with Liqui-Nox quarterly, or more often as needed. Record quarterly cleanings in the LIMS.