Can I use QIAprep Miniprep kits for low-copy plasmids and cosmids?
FAQ ID -127

All QIAprep Miniprep Kits can be used for preparation of low-copy number plasmids and cosmids up to 50 kb. Below are recommendations for processing low-copy constructs using QIAprep technology:

  • Use up to 10 ml overnight E. coli cultures grown in LB medium
  • Be sure to include the optional Buffer PB wash step for all bacterial strains
  • When plasmids or cosmids are larger than 10 kb, pre-heat Buffer EB (or water) to 70°C prior to eluting DNA from the QIAprep membrane
  • When using 10 ml culture volume, it is recommended to double the volumes of Buffers P1, P2, and N3

See also QIAGEN News 1998, Issue 5 for an article entitled 'Isolation of a low-copy plasmid from agrobacterium using QIAprep technology'. Alternatively, the R.E.A.L. Prep 96 Plasmid Kit can be used for high-throughput purification of larger plasmids (e.g., BACs, PACs, and P1s). See QIAGEN News 1999, Issue 2 for an article entitled 'High-throughput purification of BACs with the new R.E.A.L. Prep 96 protocol'.