PCR vs. DNA sequencing

1. The difference of the objective

PCR: Used to make more of the DNA.

DNA sequencing: Has the DNA strands stop at certain A’s, T’s, C’s and G’s.

2. At some point, each process uses Gel electrophoresis

PCR: To separate the truncated strands from the longer strands.

DNA sequencing: To find out the location of each adenine, thymine, guanine, and cytosine on the DNA strand.

3. Number of test tubes used

PCR: At least one test tube is needed as one just puts all the tools and waits for an hour to get the amplified DNA

DNA sequencing: Four test tubes are used in DNA sequencing for each nitrogenous base: adenine, thymine, cytosine, and guanine.

4. Each process uses the same tools with one major difference

PCR: Needs some modified polymerase, lots of nucleotides and short pieces of single-stranded DNA as primers, along with the DNA fragment.

DNA sequencing: Needs all of the tools of PCR plus the dideoxynucleotides: ddATP, ddCTP, ddGTP, and ddTTP, to terminate elongation because dideoxynucleotides do not have a hydroxyls like in DNA or RNA.

5. Each process has a different result

PCR: A large amount of the amplified DNA is obtained for use to detect mutations, when you need to recombine, when you need to find out who the daddy is and when you need to solve a crime.

DNA sequencing: The sequence of adenine, thymine, cytosine, and guanine of the DNA strand is revealed.