Perform steps 1-7 in the tube provided.
- Thaw a tube of competent E. coli cells on ice for 10 minutes.
- Add 1-5 μl containing 1 pg-100 ng of plasmid DNA to the cell mixture. Carefully flick the tube 4-5 times to mix cells and DNA. Do not vortex.
- Place the mixture on ice for 30 minutes. Do not mix.
- Heat shock at exactly 42°C for exactly 30 seconds. Do not mix.
- Place on ice for 5 minutes. Do not mix.
- Pipette 250 μl of room temperature SOC into the mixture.
- Place at 37°C for 60 minutes. Shake vigorously (250 rpm) or rotate.
- Warm selection plates to 37°C.
- Mix the cells thoroughly by flicking the tube and inverting, then perform several 10-fold serial dilutions in SOC.
- Spread 50-100 μl of each dilution onto a selection plate and incubate overnight at 37°C. Alternatively, incubate at 30°C for 24-36 hours or at 25°C for 48 hours.