1. Grow 2 ml of the bacteria host overnight in LB medium
2. OPTIONAL: On the next morning, transfer the culture to a microtube and heat shock the culture for exactly 15 min at 42ºC
3. Chill the culture in ice slurry for 10 min. For now on, all procedures are made at 4ºC
4. Harvest cells at 10,000 rpm for 3 min. Resuspend in 1 ml of ice-cold and centrifuge again. Repeat this step twice more.
5. Resuspend bacteria in a final volume of 50 μl in ice cold
6. Electroporation is made in a prechilled 0.2 ml cuvette in the Bio-Rad electroporator according to the manufacturer instructions.
7. Following electroporation, immediately add 2 ml of SOC (2% tryptone, 0.5% yeast extract, 10 mM NaCl, 10 mM , 10 mM ) or LB.
8. Cells are transferred to a tube and incubated at 37ºC for at least 1h to allow expression of the AbR phenotype.
9. Plate 0.1-2 ml bacteria on the appropriate antibiotic plates and incubate O.N. at 37ºC.