Use the same concentration as for agar plates ie 0.037 Lb.Agar for 1 ml water.
Storage of E. coli colonies in stab agar for short-term storage/transport Most strains of E. coli can be stored for one to two years in stab agar. This is ideal for transport when –20 to -70°C storage in glycerol is impossible.
1. Use airtight, centrifuge tubes or autoclaved vials containing 2/3 full (approx. 1 ml) of medium. Autoclavable cryovials are ideal for this.
2. Inoculate each vial with a single colony by picking a single colony with a sterile toothpick and lightly stabbing it into the media. You do not need to penetrate the agar more than a few mm.
3. Leave the cap of the vial sightly loose and incubate overnight at 37° C.
4. Seal the vial tightly and stored at room temperature in a dark place.
5. To revive a stored strain, streak onto LB plate containing appropriate antibiotics for a single colony and incubate overnight at 37° C.