make 'em competent

- grow in LB to OD450 0.5-0.7
- 15' on ice
- 5' 8000 rpm (or 10' 4500 rpm), 4 C
- pellet into 20 ml cold (ice) 10 mM CaCl2
- 5' 8000 rpm (or 10' 4500 rpm), 4 C
- pellet into 20 ml cold (ice) 50 mM CaCl2
- 20' on ice
- 5' 8000 rpm (or 10' 4500 rpm), 4 C
- pellet into 4 ml cold (ice) 50 mM CaCl2
- make aliquots of 200 ul

plug in DNA

- add DNA to 200 ul competent cells
- 45' on ice
- 2' 42 C
- 5' on ice
- ad 1 ml LB
- 1h 37 C
- plate out one drop, use rest for controls etc.