One-Step Preparation of Competent E. Coli

Get a printable version of this protocol (requires Adobe Acrobat) 

1. Grow cells in LB to early exponential phase (OD=0.3-0.4).
2. Pellet cells by centrifugation at 1000g for 10 min. at 4ºC.
3. Resuspend cells in one tenth their original volume in ice-cold TSS solution.
4. For storage, freeze immediately in liquid nitrogen and store at -70ºC.