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Procedure (for E. coli XL2-Blue)

  1. Thaw cells
  2. Pipette 50 ul of cells into an ependorff
  3. With gentle stirring, pippette 5 ul of a 20 ul (about 100 ng? *****) ligation reaction into the ependorff
  4. Place the ependorff on ice for at least 30 minutes
  5. Heat shock the transformation mixture for 45 seconds at 42*C
  6. Put the transformation mixture on ice for 2 minutes
  7. Add 400 ul of sterile YT to the transformation mixture
  8. Mix gently by inverting several times
  9. Incubate at 37*C for at least 45 minutes
  10. Centrifuge at full speed for 2 minutes
  11. Discard 300 ul of the supernatant
  12. Resuspend the pellet in the remaining 150 ul
  13. Plate and incubate at 37*C overnight


  • You can do a cheap-o transformation to quickly check something by incubating 100 ng of DNA with cells for 30 minutes then incubate O/N at 37°C