Title: Reagents in PCR - review
Course: BTEC-1100-301-302-303-F21 > Section: Module 3 - Polymerase Chain Reaction

There are just a few reagents needed for PCR. First and probably most importantly you need a sample of DNA that is be amplified. This is called the target DNA or more specifically the template DNA because it is the template that will be copied from. This can be any DNA provided it is of sufficient quality and you only need one single molecule of the template to be copied. In the lab we typically use nanogram (10^-9) or even picogram (10^-12)  quantities of DNA as a starting point.

The following reagents are required for a successful PCR:

1. Template DNA. This is the source DNA that you want to copy from and contains your target sequence or gene of interest.
2. Forward and reverse primers. These are short single stranded DNA molecules that are complementary to the target sequence.
3. Taq polymerase. This is the enzyme that copies the DNA, it is a DNA polymerase.
4. Deoxynucleotide triphosphates (dNTPs). These are the building blocks of DNA that are assembled by the Taq polymerase. We know them as A, C, G andT
5. PCR buffer. This is a buffer that has optimal chemical conditions for the Taq polymerase to function.
6. Magnesium chloride. Magnesium chloride is important for helix formation in DNA and for primer annealing to the target sequences.