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Transformation bacteria heat chock and incubation? - (Oct/05/2011 )


Ive recently been introduced to the
method of applying a plasmid into
"competent" bacteria using the heat chock method

In my lab papers its said that these after heat chock is
incubated at 37 degrees celsius at 45 min

My question is what is this process of incubation for
after the heat chock process to make plasmids go into
bacteria. why do you incubate bacteria after heat chock?



I was taught that incubation at 37 °C is needed for the bacteria to kind of relax and start the replication and transcription of the plasmid and plasmid encoded genes. This is especially important for the expression of the antibiotic resistance which is needed for the bacteria when you plate them onto the plates.


The heat shock process actually does damage to the outer membrane of the bacteria, and the cells do need some time to recover after that. But more importantly, the bacteria need time to make the antibiotic resistance protein (encoded on the plasmid) before being exposed to the antibiotic. If the cells are plated on an antibiotic that will kill them, they will die before they have time to synthesize enough protein to counteract the antibiotic.

Best of Luck.