IGEM:Peking/2007/Switch: DNA rescue by precipitation

DNA rescue by precipitation
1．	Add 2 volume times of 100% ethanol in the system, 1/10 volume times of 3M NaAc. Some time later DNA will precipitate. For vectors, generally speaking the time is shorter than 30 minutes. For fragments shorter, the time needed for precipitation is longer. If some fragment shorter than 100bp need precipitate, same volume of isopropanol and 1/10 volume of 3M NaAc should be added and precipitation process need overnight.

2．	centrifuge for 12，000rpm, 15min

3．	Discard the supernatant

4．	Add 200uL 70% enthol to wash.

5．	centrifuge for 12，000rpm, 10min

6．	Discard the supernatant

7．	Dry it under 37 degrees

8．	Dissovle it in some volume of ddH2O, say 20uL.