Jump to section:

Key Concepts

To create larger quantities of plasmids for isolation, liquid cultures are preferable to plates. Each colony on a plate in theory grew from a single bacterium. This means that all the cells in a single colony should be genetically identical. By putting at least one cell in a colony into liquid media, the cell should be able to grow and saturate the media overnight.


  • Plates from transformation with individual colonies
  • Liquid LB media in bacterial culture tube
  • 1000X Kanamycin stock


  1. Add 1000X kanamycin to the LB so that the final concentration is 1X. Swirl to mix.
  2. Using a pipette tip, touch a single colony on the plate.
  3. Touch the pipette tip to the LB in the bacterial culture tube and lightly swirl. At least one cell must remain in the media.
  4. Grow at 37°C overnight while shaking.