Polymerase Chain Reaction (PCR)

single template strand

In theory, only a(n) ________ is needed to copy and generate millions of new identical DNA molecules.

Denaturation step

________: the thermal cycler heats the sample to 94°C, so the template strands separate (denature)

Extension step

________: the thermal cycler heats the sample to 72°C for Taq DNA polymerase to extend the primers and make complete copies of each template DNA strand.

PCR

________: procedure that amplifies a specific sequence of DNA.

precise length

It is the ________ strands generated from the intermediate strands that amplify exponentially at each cycle.

PCR

________ has made an impact of four main areas of genetic research: gene mapping, cloning, DNA sequencing, and gene detection.

PCR involves a repetitive series of cycles, each of which consists of

template denaturation, primer annealing, and extension of the annealed primer by Taq DNA polymerase.

PCR

procedure that amplifies a specific sequence of DNA

PCR has made an impact of four main areas of genetic research

gene mapping, cloning, DNA sequencing, and gene detection

Thermal cyclers

contain an aluminum block that holds the samples and can be rapidly heated and cooled across extreme temperature differences

Temperature/thermal cycling

the rapid heating and cooling of this thermal block

Denaturation step

the thermal cycler heats the sample to 94°C, so the template strands separate (denature)

Annealing step

the thermal cycler then rapidly cools to 60°C to allow the primers to anneal to the separated template strands; the two original template strands may reanneal to each other or compete with the primers for the primers complementary binding sites

Extension step

the thermal cycler heats the sample to 72°C for Taq DNA polymerase to extend the primers and make complete copies of each template DNA strand

Temperature cycle =

denaturation step + annealing step + extension step