Wednesday 22^nd June

Lab work

Heat-shock competent cells (cf. protocol)

By Marion

At 10am OD was 0.3. At 1pm OD was 0.46. At 3pm OD was 0.62.

The solution was put on ice 10min (in order to stop the OD). After, it was centrifuged 10min at 4°C at 3000rpm. The pellet was resuspended in 80mL ice-cold TB and incubated on ice for 10min. The solution was centrifuged again at 4°C at 3000rpm. The pellet was resuspended in 20mL ice-cold TB and DMSO was added at 7% of the final concentration (1.58mL of DMSO for 21mL of TB+cells). The solution was incubated on ice for 10min and then distributed in tubes, frozen in liquid nitrogen and stored at -70°C.

Interlab study

Transformation

By Lea and Caroline

No colony grew on the Petri dish. Transformations have to be done again. The usual protocol was followed but this time 2µL of plasmids were taken, a new solution of antibiotic Cm was used and a positive control was added (a pSB1C3 plasmid).