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Name: Jeff R.
Status: Student
Age: 20s
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Date: N/A 


Question:
When electroporating E. coli cells, why aren't the bacteria killed by the electrical shock? If they aren't killed because the voltage isn't high enough, what is the highest level before the bacteria are killed? Also, how is it that "shocking" bacteria allows plasmid DNA to enter the cell? Thanks



Replies:
During electroporation the bacteria are not killed because the shock lasts for miliseconds only. If the shock lasts longer, the temperature rises too much and viability decreases (another way of saying that bacteria are killed). How exactly this makes DNA enter the cells is unclear. It is thought that the electrical field 'pulls in' the DNA (a charged molecule), but this is a plastic visualization of a process we do not fully understand. More important is that it works, and it is an efficient way of bringing DNA (either plasmids or fragments of chromosomal DNA) into a cell.

Dr. Trudy Wassenaar



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