KA 1.2: polymerase chain reaction (PCR)

What does PCR do?

PCR amplifies DNA using compmentary primers for specific target sequnces.

What are primers in PCR?

In PCR primers are short strands of nucleotides which are complementary to specific traget sequneces at the two ends of the region of DNA to be amplified.

What are practical applications or PCR?

PCR can amplify DNA to help solve crimes, settle paternity suits and diagnose gentic disorders

Step 1 of PCR ?

• DNA is heated between 92° C and 98° C to sperate the strands

Step 2 of PCR

• It is then cooled to between 50° C and 65° C to allow primers to bind to target DNA seqeunces

Step 3 of PCR?

• It is then heated between 70° C and 80° C for heat -tolerant DNA polymerase to replicate the region DNA

Step 4 of PCR?

1. This repeated cycle of heating and cooling amplify this region of DNA (number of DNA molecules double each time)