Quick 'n dirty CaCl2 comp cells preparation

Plasmid transformations only, OK!?

• Overnight: Grow 1 ml culture overnight at 37°C.
• Subculture 1:100 in LB a 125 ml flask. Shake at 37°C until 0.3 < OD600 < 0.6 (usually 2.5 hours)
• Pellet 1mL culture in eppendorf, spin for 3 min at 4000 xg.
• Resuspend cells in 100ul of ice cold 100mM CaCl2. Let sit for no more than 10 minutes.