Three estrogens are present in the plasma of the human female: 

1β-estradiol

 Estrone

Estriol

#Id: 2547

#Unit 13. Methods in Biology

Primer sequence also· affects PCR efficiency. For example, if the primers used for PCR have complementary regions, primer dimers will be formed, and PCR efficiency will markedly decline.

#Id: 2548

#Unit 13. Methods in Biology

The sequence of the target DNA itself can affect PCR efficiency. The GC-rich sequences in target DNA may form secondary structures in the single strands produced by denaturation; this could reduce PCR efficiency.

#Id: 2549

#Unit 13. Methods in Biology

7-dcaza guanosine triphosphate (7-deaza OTP) can be used in place of OTP; it reduces hairpin loop formation without affecting the Watson-Crick base pairing required for annealing and primer extension. 

#Id: 2550

#Unit 13. Methods in Biology

Addition of certain proteins, such as, bovine serum albumin enhances efficiency by protecting the DNA polymerase and by binding to PCR inhibitors. 

#Id: 2551

#Unit 13. Methods in Biology

5′ nuclease assay (TaqMan assay). PCR is undertaken with a fluorescence reporter/quencher pair (called RQ probe). 

#Id: 2552

#Unit 13. Methods in Biology

During extension by Taq polymerase, the probe is cleaved owing to the nuclease activity of the polymerase.