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There are several steps that are crucial for the efficient updtake of plasmid DN

ID: 177383 • Letter: T

Question

There are several steps that are crucial for the efficient updtake of plasmid DNA by bacterial cells and subsequent growth of the cells containing the plasmid. Place arrange each of these steps in sequential order. Remember, they are NOT necessarily listed in the order you would do them during the procedure.

A. Heat shock of bacteria at 42ºC for 90 seconds

B. Incubation of bacteria with plasmid on ice

C. Incubation of cells/DNA at 37ºC for 1 hour

D. Spread cells onto agar plates

What is the purpose of the heat shock step during the above procedure?

To facilitate the attachment of the plasmid DNA to the outer surface of the bacteria

To facilitate the entry of the plasmid DNA into the bacteria

To improve the efficiency of the enzyme digestion

Unknown

To facilitate the attachment of the plasmid DNA to the outer surface of the bacteria

To facilitate the entry of the plasmid DNA into the bacteria

To improve the efficiency of the enzyme digestion

Unknown

Explanation / Answer

To facilitate the entry of the plasmid DNA into the bacteria. The heat shock produces a pressure difference inside and outside the cell and it creates a hole in the cell and helps the entry of the plasid into the cell, and once the temparature becomes normal the hole will be sealed.