PCR VS Vector Cloning

SIMILARITIES

1.    Both techniques are used to a DNA segment that contains the gene of interest and make copies of them.

2.    The number of copies of targeted strands begins to increase exponentially.

DIFFERENCE

PCR (Polymerase Chain Reaction

1.    Direct method of amplifying copies of a desired DNA sequence without using cells.

2.    PCR requires three steps:

Heating – As temperature rises in the range of 94 – 96 degrees Celsius, the hydrogen bonding between nitrogen bases break causing the DNA strands to separate.

Cooling – Temperature is cooled down to the range of 50 – 65 degrees Celsius for the primers to anneal with the strands (template DNA).

Replication – A special DNA polymerase builds complementary strands using free nucleotides and the elongation is initiated by DNA primers.

3.    Taq polymerase, which is isolated from a bacterium that lives in hot springs, is used to elongate the new DNA strand.

4.    PCR requires less time compared to the vector cloning.

5.    By the third cycle, the number of copies of the targeted strands begins to increase exponentially.

Vector Cloning

1.    Appropriate restriction enzymes are needed to excise a gene fragment from the source DNA. More than one RE may b used at one time.

2.    A plasmid of a bacterium is cut open using a RE, producing sticky ends. Then DNA fragment and plasmid is joined by DNA ligase.

3.    Bacterium is used often utilized as a host organism because they reproduce fast, easy to obtain and their plasmid is very stable.

4.    The introduction of DNA from another source into a host cell is known as transformation.

5.    Vector cloning is relatively cheaper than PCR.