Our plasmid transformation protocol is as follows:
a) Place one 1.5 ml tube containing 50 μl competent cells (stored at -80°C) and thaw it on ice for 20-30 min.
b) In the meantime, dissolve the lyophilized 4 μg plasmid with sterilized water to make a concentration of 100 ng/μl.
c) Mix 2-3 μl of plasmid with the competent cells by tapping the tube.
d) Place the tube on ice for 12-15 min.
e) Heat shock the mixture by placing two-thirds of the tube into a 42°C water bath for 2 minutes.
f) Return the tube back on ice for 2 min.
g) Add 800 μl LB and shake in a 37°C incubator (200 rpm) for 40 min.
h) Plate some or all of the transformation mixture onto a LB agar plate containing antibiotic.
i ) Incubate plates at 37°C overnight.
