ASCP Technologist in Molecular Biology 2

Question 1

What is the principle behind polymerase chain reaction (PCR)?

Accepted Answer

Amplifying specific DNA sequences through repeated cycles of denaturation, annealing, and extension

Answer

PCR amplifies specific DNA sequences exponentially through thermal cycling: denaturation, annealing, and extension.

Question 2

What is the difference between real-time PCR (qPCR) and conventional PCR?

Accepted Answer

qPCR monitors amplification in real-time using fluorescent probes, enabling quantification

Answer

Real-time PCR uses fluorescent reporters to monitor amplification during each cycle, enabling quantification of starting template.

Question 3

What is the purpose of reverse transcriptase in RT-PCR?

Accepted Answer

To convert RNA into complementary DNA (cDNA) before PCR amplification

Answer

Reverse transcriptase synthesizes cDNA from an RNA template, enabling RNA viruses and gene expression to be detected by PCR.

Question 4

Which molecular technique detects specific DNA sequences by separating fragments and transferring them to a membrane?

Accepted Answer

Southern blot

Answer

Southern blotting separates DNA fragments by gel electrophoresis, transfers to a membrane, and hybridizes with a labeled probe.

Question 5

What is next-generation sequencing (NGS) and how has it impacted clinical diagnostics?

Accepted Answer

Massively parallel sequencing of millions of DNA fragments simultaneously

Answer

NGS performs massively parallel sequencing of millions of fragments, enabling comprehensive genomic analysis at unprecedented speed.

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