Bio-Rad Ligation and Transformation Module - Manual (Page 39)

b. Prepare starter culture: As late as possible the day before the
transformation, inoculate a 2–5 ml LB culture with a starter colony
from the
E. coli starter plate. Incubate cultures in a shaking water
bath or incubator overnight at 37°C and at least 200 rpm.
Note: It is important to use a fresh starter culture (<24 hours since
inoculation) for the transformation, or transformation efficiency will be
reduced.
Note: If a shaking water bath or incubator is not available, incubate starter
cultures at 37°C 1 day prior to the transformation, manually shaking the
vial containing the culture as frequently as possible to oxygenate the
culture (a reduction in transformation efficiency may be observed).
3. Place 1 LB Amp IPTG agar plate per student team in 37°C incubator
just before the transformation lab. Note: If performing a positive control
transformation, a second plate per student team will be needed.
4. Pipet 1.5 ml of C-growth medium to one 15 ml culture tube per team
and incubate at 37°C for at least 10 min prior to the transformation
laboratory.
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