Sterility test

Inactive samples can only be removed from the lab after undergoing sterility testing, which must be countersigned.

To prove that the sample, such as extracted DNA for PCR analysis, is completely sterile, the following steps must be completed:

• 10% of the liquid sample must be cultured on agar and stored for one week at 37°C.

• This should then be checked for colonies. Even if none are observed, the entire agar needs to be swabbed. The swab is then placed in a liquid culture for one week at 37°C.

• After this week, the culture is then checked for growth/cloudiness. Even if nothing is observed, it should be looked at under a microscope, at which point if no growth is visible, the solution is deemed sterile.