Medical Laboratory Technician Exam Molecular Diagnostics 2

Question 1

FISH (Fluorescence In Situ Hybridization) is primarily used to detect:

Accepted Answer

Chromosomal abnormalities and gene rearrangements

Answer

Bacterial contamination in blood cultures

Answer

Viral load in serum

Answer

Point mutations in mitochondrial DNA

Question 2

The BCR-ABL fusion gene detected by molecular methods is associated with which condition?

Accepted Answer

Chronic myelogenous leukemia (CML)

Answer

Acute lymphoblastic leukemia only

Answer

Multiple myeloma

Answer

Hodgkin lymphoma

Question 3

DNA sequencing by the Sanger method uses which modified nucleotides to terminate chain elongation?

Accepted Answer

Dideoxyribonucleotides (ddNTPs)

Answer

Deoxyribonucleotides (dNTPs)

Answer

Ribonucleotides (rNTPs)

Answer

Phosphorylated nucleotides

Question 4

Which quality control measure is most important in a molecular diagnostics laboratory to prevent false-positive results?

Accepted Answer

Strict physical separation of pre- and post-amplification areas

Answer

Using heat-inactivated samples

Answer

Running all samples in duplicate

Answer

Using only fresh specimens

Question 5

What is a molecular beacon probe in real-time PCR?

Accepted Answer

A hairpin-shaped probe with a fluorophore and quencher that fluoresces when hybridized

Answer

A linear probe that binds to the amplicon

Answer

A radioactively labeled DNA probe

Answer

A protein probe that binds DNA

Question 6

Next-generation sequencing (NGS) differs from Sanger sequencing primarily in that NGS:

Accepted Answer

Sequences millions of DNA fragments simultaneously in a massively parallel manner

Answer

Can only sequence short fragments of DNA

Answer

Requires more sample volume than Sanger

Answer

Is less accurate than Sanger sequencing

Question 7

A positive internal control in a PCR assay serves to:

Accepted Answer

Verify that PCR inhibitors in the specimen did not prevent amplification

Answer

Confirm the target sequence is absent

Answer

Indicate sample contamination

Answer

Determine the melting temperature of the amplicon