Technologist in Molecular Biology Flashcards

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

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

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

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

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

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

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

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

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

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

Answer: Southern blot

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

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

Answer: Massively parallel sequencing of millions of DNA fragments simultaneously

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

What is FISH (fluorescence in situ hybridization) used for?

Answer: Detecting specific DNA/RNA sequences in cells using fluorescent-labeled probes

FISH uses fluorescent-labeled DNA probes that hybridize to specific chromosome regions, enabling visualization of chromosomal abnormalities.