The transformation of Bacillus subtilis

- thaw one aliquot at 37 °C
- use these cells to inoculate 20 ml LS medium
- shake cells slowly in a 30°C water bath to obtain maximal competence (about 2 h)
- take 1 ml aliquots into a glass tube or 2 ml Eppendorf tube, add 10 μl of 0.1 M EGTA (CB-0732-10GAM), and incubate for 5 min at room temperature
- add plasmid or chromosomal DNA and incubate for 2 h at 37°C while well shaking (well mixing is important when using Eppendorf cups)
- if glass tubes were used, transfer cell suspension into an Eppendorf tube
- centrifuge, discard supernatant carefully and resuspend the cells into the final supernatant remaining on the pellet
- plate on selective 2xYT medium
- incubate at 37°C overnight