Protocols Metabolism

The following page give an overview of the standard protocols used by the team Metabolism in iGEM PET.erminators project 2012.

Protocols Metabolism

In vivo

Production of chemically competent cells

Production of chemically competent cells

• Inoculate 10 ml of LB-Media with an E. coli colony and incubate at 37 °C overnight
• Inoculate 200 ml of LB-Media with 2.5 ml of the overnight culture
• Incubate the culture at 37 °C until an OD600 of 0.5
• Cool the cells on ice for 5 min
• Centrifuge the cells for 10 min at 5000 rpm and 4 °C
• Resuspend the cell-pellet in 32 ml pre-cooled CaCl₂ solution (Do not vortex!)
• Add pre-cooled CaCl₂ solution to 200 ml
• Let the cells repose on ice for 1 hour
• Centrifuge the cells for 10 min at 5000 rpm and 4 °C
• Resuspend the pellet in 10 ml cryo-solution
• Decant 200 µl of competent cells in a 1.5 ml tube
• Store the tube in an -80 °C freezer

Solutions

• CaCl₂
  • 5.55 g CaCl₂
  • Add di H₂O to 1 L
  • Sterilize by autoclaving

• Cryo solution
  • 0.278 g CaCl₂
  • 10 ml glycerin
  • Add di H₂O to 50 ml
  • Sterilize by autoclave

Heat shock transformation with E. coli

• Thaw the chemically competent cell on ice
• Add 50 – 300 ng of the purified plasmid or 1-5 µL of the heat inactivated ligation mix to the cells (10 – 500 ng DNA)
• Invert the tube up to 6 times
• Incubate the cells on ice for 30 min
• Incubate the cells for 1 min at 42 °C
• Let the cells cool down on ice for 5 min
• Add 800 µl of SOC Media
• Incubate the cells for 45 min at 37 °C
• Centrifuge for 5 min at 0.4 rcf
• Resuspend the pellet in 100 µl LB-Media and plate it on LB Agar with antibioticum

Glycerine stock

• Add 200 µl of sterilized glycerine to 800 µl cell culture and mix well
• Freeze the stock at -20 °C