The Aim of this lecture is to present on to understand the process of Polymerase Chain Reaction (PCR) and its uses. Polymerase chain reaction enables large amounts of DNA to be produced from very small samples (0.1ml). There is a repeating cycle of: separation of double DNA strands and synthesis of a complementary strand for each. Sample DNA , nucleotides, DNA primers & thermostable DNA polymerase placed in PCR machine. Strands of sample DNA separated by heating to 95oC. Mixture cooled to 37oC to allow primers to bind.