Qiagen cosmid prep

  1. Grow 25 ml cells in appropriate antibiotic overnight in a flask.

  2. Spin down cells at 6000 rpm in Hermle at 4°C for 10 min.

  3. Discard supernatant and resuspend in 0.9 ml P1

  4. Divide resuspended cells into three 1.5 ml microfuge tubes

  5. Add 0.3 ml P2 to each tube (per Qiagen protocol).

  6. Add 0.3 ml P3 to each tube (per Qiagen protocol).

  7. Incubate on ice for 15 min (per Qiagen protocol).

  8. Pellet precipitate, spin 15 min at 4°C (per Qiagen protocol).

  9. Prepare Qiagen mini column (per Qiagen protocol).

  10. Pool supernatant from the three tubes onto ONE Qiagen column.

  11. Proceed with Qiagen mini protocol

  12. Resuspend DNA in 25-40 l TE, depending on size of pellet.