1. Set the starter culture (5ml LB/amp) from single colony ON.
2. Add 1 ml of starter culture to 500 ml LB/amp. Grow ON.
If amplifying add 500l of CAM when culture is dense enough.
3. Continue incubation @ 37C ON
4. Spin down the ON culture (10 min @ 4K) & resuspend it
in 10 ml of Sol I
5. Incubate @ RT for 5 min.
6. Add 20 ml of freshly made Sol II to each tube, and mix
gently by inverting.
7. Incubate on RT for 10 min.
8. Add 15 ml of Sol III to each tube, mix gently by inverting.
9. Incubate on ice for 5 min.
10. Spin down 30-60 min @ 10K.
11. Transfer supernatant carefully to 40 ml tube and spin
30 min @ 13K.
12. Pour supernatant to two 40ml tubes through kimwipe.
13. Add 0.6 volumes of 99% isopropanol to each tube, mix
several times by inverting and incubate on RT for 15 min.
14. Spin DNA down 30 min @ 13 K at RT. If centrifuged @ 4 C
salt may precipitate.
15. While that is spinning add 0.5 ml EtBr to Nalgene tube.
16. Resuspend DNA from each tube in 3.75ml H₂O.
17. Combine DNA from two tubes (total 7.5 ml), add 8.5g CsCl to it.
18. When CsCL is dissolved transfer it to a Nalgene tube.
19. Make sure that tubes weigh the same!
20. Seal Nalgene tubes and spin 48 hours @ 48 K RPM.
21. Go and party for 2 days and nights.
22. Recover DNA by syringe into 15 ml tubes.
23. Wash 4-5 X with 80% isopropanol
(always discard the upper phase).
24. Add two volumes of H₂O & transfer it to a 40 ml tube.
25. Add 3 volumes of cold 95% EtOH.
26. Mix by inverting and incubate 1hr - ON @ -20 C.
27. Spin down 30 min @ 13 K RPM.
28. Mark position of DNA, pour off supernatant & dry with
sterile cotton tip.
29. Add 1 ml of H₂O, resuspend DNA & transfer it to a 1.5 ml tube.
30. Take 10 l into new tube and add 990 l H2O
31. Measure OD260 of that.
32. Multiply results of OD260 with 5000 to get g/ml.
* 1 OD260 = 50microg/ml
33. If it worked, repeat step 21.

Note: This protocol is considered to be outdated by many, but if you need large amounts of high quality DNA you might want to try it.