CONCENTRATION: Quality Control

1. Check the liquid reagents each time they are used; the formalin and saline should appear clear, without any visible contamination.

2. The microscope should be calibrated (within the last 12 months), and the objectives and oculars used for the calibration procedure should be in place on the microscope when objects are measured. The calibration factors for all objectives should be posted on the microscope or close by for easy access. Although some feel a microscope does not require calibration every 12 months, if the microscope is moved periodically, can be easily bumped, or does not receive adequate maintenance, it should be rechecked yearly for calibration accuracy.

3. Known positive specimens should be concentrated and organism recovery should be verified at least quarterly, and particularly after the centrifuge has been recalibrated.