Pouring plates

Once the agar has been sterilised and cooled, it is ready to pour.  There were a surprising number of things to remember when pouring plates.  When using a one of semi sterile units, it is important to: (1) keep your head out from under the hood (difficult for a short person like myself); (2) wipe down the bench before commencing work; (3) turn the gas on, light the burner and pass the mouth of the bottle through the flame; (4) work from side to side, not front to back; (5) store petri dishes containing bacteria with the agar uppermost and petri dishes containing fungi with the agar on the bottom; (6) turn the gas off at the wall when finished.

As a guide, 500ml of agar will be enough for 20 petri dishes.   I had 38 to plate, but I had a significant amount left over by the time I had finished.  This indicated that I had not poured enough in each petri dish, and that the growing medium would be too thin, ie, insufficient food for the bacteria to grow for a sustained period.

Plates poured with agar cooling under sterile hood.

Plates kept in refrigerated storage ready for use - very proud to see my name featuring.