OWML: QA/QC

Quality Assurance/Quality Control Manual: Ohio Water Microbiology Laboratory

Hoods
The Ohio Water Microbiology Laboratory (OWML) has four types of hoods— (1 and 5) two biosafety cabinets, (2) a laminar-flow hood, (3) a hazardous-waste fume hood, and (4) a PCR workstation. To ensure proper use of hoods 1, 2, 3 and 5, “quick check” criteria for properly running each hood are posted on the hoods.

• The operation of all hoods are checked and certified by a qualified inspector annually and recorded in the LIMS.
   

The biosafety and laminar flow hoods have magnehelic pressure gauges (MAG) that are used to monitor operation of the hoods. When using these hoods, check to make sure the pressure gauge is reading at a level approximately equal to the annually recorded MAG level on the calibration sticker. A significant increase in pressure indicates that the filters are dirty whereas a significant decrease in pressure indicates an electrical problem.

The biosafety cabinets, laminar-flow hood, and PCR workstation (Hoods 1, 5, 2, and 4) must be free from contamination by live organisms.

• The working surfaces of the biosafety cabinets, the laminar-flow hood and the PCR workstation (Hoods 1, 5, 2, and 4) are wiped down with a surface disinfectant, such as Conflikt or 70 percent ethanol before and after general use. When working with pathogenic organisms, the hoods are wiped down with Dispatch Hospital Cleaner Disinfectant towels with bleach (Caltech Industries Inc., Midland, MI) followed with 70 percent ethanol. For the biosafety cabinets, be sure to lift up the work surface and clean under this area monthly. Monthly internal cleaning of the biosafety cabinets are recorded in the LIMS.
   
• The biosafety cabinets and PCR workstation (Hoods 1, 5 and 4) have ultraviolet bulbs for germicidal purposes. The ultraviolet lights in the biosafety cabinets and PCR workstation are cleaned quarterly by wiping the bulbs with a soft cloth. Cleaning dates are recorded in the LIMS. A bulb that is dull in the center needs to be replaced. Record the bulb change in the LIMS.
   
• Biannually, nonselective agar plates are exposed to airflow in the laminar-flow hood, the biosafety cabinets, and PCR workstation for 1 hour (Hoods 1, 5, 2, and 4). The plates are incubated at 35oC for 24 hours and examined for contamination. The results are record in the LIMS.
   

The hazardous-waste fume hood (Hood 3) must be checked to ensure that it is operating properly.

• Check the operation of the hazardous-waste fume hood (Hood 3) quarterly by use of fume cartridges and record results in the LIMS.
   
• A KimWipe is taped to the outside of the hood sash as a quick check for proper airflow.