# Difference between revisions of "Transforming chemically competent cells"

Also see Preparing chemically competent cells

## Method

1. Thaw TSS cells on ice.
2. Add DNA, pipette gently to mix (1μl of prepped plasmid is more than enough).
• Note: If you are adding small volumes (~1μl), be careful to mix the culture well. Diluting the plasmid back into a larger volume can also help.
3. Let sit for 30 minutes on ice.
• Note: If you are in a rush, you can shorten this incubation time to 5-10 min.
4. Incubate cells for 30 seconds at ${\displaystyle 42^{o}}$C.
• Note: According to the original TSS paper and qualitative experience (JM), this step is completely optional and may actually reduce transformation efficiency.
• I tested this with DH5a Z1 and pUC19 and found that heat shock at 42C for 30 sec improved transformation efficiency 10-fold (Paul Jaschke)
5. Incubate cells on ice for 2 min.
6. Add 1 mL SOC (2XYT and LB are also suitable, original paper suggests LB + 20mM glucose) at room temp.
7. Incubate for 1 hour at ${\displaystyle 37^{o}}$C on shaker.
• Note: Can also save some time here by reducing incubation to ~45 min.