Team:EPF-Lausanne/Notebook/2 September 2012

From 2012.igem.org



Contents

Transformation of ligations

Protocol: E.Coli Transformation


  1. Thaw the competent E.coli (DH5alpha) cells on ice (not in hands!)
  2. As soon as it is thawed, add 50µl of the cells to the DNA (~50-100 ng of pure plasmid, or some 2 µl usually)
  3. Let it rest on ice for 20-30 min. Meanwhile, put agar plate (with correct antibiotic) at 37°C for prewarming.
  4. Put the tube with DNA+E.coli at 42°C for 45 sec - 1 min (heat shock)
  5. Add 400 µl of LB broth and place at 37°C for 20-30 min (shaking)
  6. Spread the cells on the prewarmed plate (and let it dry)
  7. Incubate the plate upside-down at 37°C for ~14-15 hours (leaving it more than 16h decreases the plasmid quality)


The pCEP4-RO and pCEP4-HA-RO ligations from the previous day were used to transform bacteria.

Overnight culture of pHY42

Protocol: Prepare Plasmid Extraction (culture for Miniprep)


  • Select and number colonies on the plates.
  • Prepare tubes of LB medium with the correct quantity of antibiotics (100 µg/ml for Amp, Spc or chloramphenicol).
    • Amp can be found in the -20ºC freezer at Ecoli, labeled as "stock". It is 100 µg/µl, or 1000x.
    • The tubes to be used are the 14 ml round bottom found in front of the iGEM drawers (Falcon). Culture with cap in the first step (loose) and close to the second step after culture.
  • Touch each colony with a clean pipette tip and put it in a tube.
  • Put in incubator.

In order to be able to make a glycerol stock for a subsequent maxiprep, we made an overnight culture of a colony from the pHY42 plate from the previous day, like the ones we do for minipreps.