There are three type of Splicing signals 

Major U2-type or GU-AG introns

Minor U12-type or AU-AC introns

Minor U12-type with GU-AG introns (hybrid type)

#Id: 2553

#Unit 13. Methods in Biology

Due to release of the reporter, there is a detectable increase in fluorescence, which is monitored in real-time PCR experiments.

#Id: 2587

#Unit 13. Methods in Biology

In case of nested PCR, the target sequence is amplified using a pair of PCR primers, and a portion of the amplification product is reamplified using another pair of PCR primers complementary to the regions located immediately beyond the 3'-ends of the first pair of primers.

#Id: 2588

#Unit 13. Methods in Biology

In case of nested PCR, the inner primers have a lower annealing temperature than that of the outer pair. For the initial several cycles of PCR the higher denaturation and annealing temperatures are used; as a result, only the outer pair of primer is able to prime amplification. 

#Id: 2589

#Unit 13. Methods in Biology

Nested PCR follows the 'drop in drop out' PCR phenomenon.

#Id: 2590

#Unit 13. Methods in Biology

Touchdown PCR, has been devised to increase the specificity of PCR without lowering the efficiency.

#Id: 2591

#Unit 13. Methods in Biology

Touchdown  PCR is initiated at very high annealing temperatures, which allow only perfectly matched primer-template DNA hybrids to form and support amplification. The annealing temperature is dropped in a stepwise fashion with each cycle of PCR.