When polymerase binding causes transition to the open complex and initiates transcription. This gives a low level of constitutive expression called the basal level. 

Binding of RNA polymerase is the rate-limiting step in this case.

TLS Online TPP Program

#Id: 2538

#Unit 13. Methods in Biology

The original template sequence will also be copied during the second and all subsequent cycles to generate the 'long product'. Therefore, the long product continues to increase linearly, while the 'correct PCR' product will multiply exponentially. 

TLS Online TPP Program

#Id: 2539

#Unit 13. Methods in Biology

In PCR, the length of primers is of great importance in ensuring that only the target sequence is amplified. 

TLS Online TPP Program

#Id: 2540

#Unit 13. Methods in Biology

In PCR, the primer length influences the rate at which primer molecules pair with template DNA; this rate decreases as the primer length increases.

TLS Online TPP Program

#Id: 2541

#Unit 13. Methods in Biology

The PCR primers must not have self complementary regions as this would lead to hairpin formation within primer molecules and make then unsuitable for PCR.

TLS Online TPP Program

#Id: 2542

#Unit 13. Methods in Biology

The partially hybridized primers may become extended by the DNA polymerase and are amplified; sometimes this may monopolize the PCR .

TLS Online TPP Program

#Id: 2543

#Unit 13. Methods in Biology

The two primers used in a PCR reaction have identical Tm for successful and specific amplification.