Pick a fresh culture from a pure culture of bacteria and inoculate it with a suspension of approximately 3-4 mcg.

How to use lyophilisation tubes safely:

1. the use of lyophilised storage tubes should be strictly required to put the lyophilised tubes into the vapour phase layer of liquid nitrogen or in the refrigerator.

2. It is recommended that you wear a lab coat, cotton gloves and operate on a safe laboratory bench. If possible, wear goggles or a protective face shield. Please take extra care as the room temperature is higher in summer than in winter.

3. During storage of frozen cells, the freezing temperature of the tubes must be uniform. Uneven freezing will result in the development of ice plugs, which will inhibit the transfer of fluid temperature on both sides, thereby creating dangerously high pressures and causing damage to the tubes.