Polymerase Chain Reaction (PCR)
Steps of PCR
100

What is PCR?

Test used to make many copies of (amplify) small sections of DNA or genes to detect the presence or absence of a gene to help identify disease/infection 

100

What are the steps of PCR?

1. Denaturation 

2. Annealing

3. Extension

200
How is PCR used in cancer research?

Can be used to amplify the genes associated with cancers from DNA 

200

What is denaturation?

-First step of PCR

-DNA is heated to 90-100C

-H-bonds between the strands of DNA broken

-DNA strands are separated (denatured)

-Single-strand used as template in annealing

300

What are the different types of PCR?

1. End-point (regular PCR)

2. Allele-specific (ARMS)

3. Reverse transcription (RT)

4. Realtime/quantitative

300

What is annealing?

-Second step of PCR

-Temp of DNA lowered to 45-65C

-primers attach to the DNA template (act as starting point for DNA synthesis) 



400

What are the characteristics of PCR?

-During early cycles of PCR, amplification is exponential (doubling)

-During later cycles of PCR amplification plateaus as components (primers or NTPs) are exhausted and become limiting 


400

What is extension?

-Third step in PCR process

-heat increased to 72C (optimal temp for Taq DNA pol.)

-Taq DNA pol. attaches to primer and builds complementary DNA strand by adding new bases 5'-3'