Polymerase Chain Reaction (PCR)
PCR reaction usually consists of 25 repeating cycles. Each cycle consist of the following stages:
• 95 C: the heat denatures the DNA, breaking the bonds that holds the strands together
• 60 C: the primers can anneal
o Form hydrogen bonds with their complementary sequences in the target DNA
• 72 C: Taq polymerase begins polymerization.
o Adding nucleotides to the 3’ end of each primer attached to DNA strand
How to replicate
Two functional roles of DNA
• Duplication: the molecule must be replicated and transmitted in each cell division
o Each daughter cell contains almost identical copies of the DNA molecules as
compared to its other cell.
Information: The molecule contains information expressed in the sequence of the
o The sequences are transcribed into RNA to release their infor