Source: Feng, Y., et al. Evaluation of a Universal Nested Reverse Transcription Polymerase Chain Reaction for the Detection of Lyssaviruses. J. Vis. Exp. (2019).
This video describes nested polymerase chain reaction, a technique that consists of two sequential PCR amplification processes using two primer sets. The first set of primers is intended to anneal to sequences upstream of the second set, resulting in selective amplification of specific gene sequences. This PCR is more sensitive and specific than a normal PCR and is widely used as a detection technique for various diseases.