Purification protocol
Notes:
- Is the RNase A solution added to the resuspension solution?
- Keep the resuspension solution cold.
- Check lysis and Neutralization buffer for salt precipitation.
- All centrifugations should be carried out at >12000 g
- Use 1-5 ml (3 ml) E.coli culture in LB media for purification of high copy plasmids.
- Resuspend the pelleted cells in 250 µl of the resuspension solution. Pipeting up and down till the cells are completely resuspended. (There is no pellet left).
Note: Ensure RNase A has been added to the resuspension buffer.
- Add 250 µl of the lysis solution and mix thoroughly by inverting the tub 4-6 times until the solution becomes viscous and slightly clear.
Note: Do not vortex, do not incubate for more than 5 minutes.
- Add 350 µl of the neutralization solution and mix immediately and thoroughly by inverting 4-6 times.
- Centrifuge for 5 min to pellet cell debris and chromosomal DNA.
- Decadent the supernatant in a new 1,5 ml tube.
- Add 650 µl of isopropanol. Invert 4-6 times.
- Centrifuge for 5 min.
- Remove isoporpanol by decanting.
- Add 500 µl of 70% ethanol, and remove by decanting.
- Let the pellet dry. You can remove some residual ethanol by pippeting.
Note: It is essential all the ethanol is removed.
- Resuspend the pellet in 50 µl water or Elution buffer.
Note: This is just a tris-buffer so it will not interfere with the ligation.
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