CSMLS Molecular Diagnostics 3

Question 1

What is the purpose of an internal control in a molecular diagnostic assay?

Accepted Answer

To detect PCR inhibition and confirm successful nucleic acid extraction

Answer

An internal control is co-extracted and co-amplified with the clinical sample; if it fails to amplify, this indicates either extraction failure or PCR inhibition, preventing false-negative reporting.

Question 2

High-resolution melt (HRM) analysis detects sequence variants by monitoring:

Accepted Answer

Changes in the melting profile of PCR products as they are heated

Answer

HRM monitors the decrease in fluorescence as double-stranded PCR product is denatured by increasing temperature; mutations alter base pairing and change the shape or temperature of the melt curve compared to wild-type.

Question 3

Loop-mediated isothermal amplification (LAMP) is advantageous over PCR in resource-limited settings because:

Accepted Answer

It amplifies target DNA at a constant temperature without thermal cycling equipment

Answer

LAMP amplifies target DNA at a constant 60–65°C using 4–6 primers recognizing 6–8 target regions, eliminating the need for a thermocycler and making it suitable for point-of-care or field testing.

Question 4

Multiplex PCR panels used in clinical microbiology laboratories are designed to:

Accepted Answer

Simultaneously detect multiple pathogens in a single reaction

Answer

Multiplex PCR includes multiple primer sets targeting different pathogens, allowing simultaneous detection of panels such as respiratory viruses or gastrointestinal pathogens from a single patient specimen.

Question 5

In clinical transplantation, high-resolution HLA typing is most accurately performed by:

Accepted Answer

Sequence-based typing (SBT) or PCR-SSO

Answer

Sequence-based typing (SBT) and PCR with sequence-specific oligonucleotide probes (PCR-SSO) provide allele-level resolution of HLA genes, enabling precise matching of donors and recipients in transplantation.

CSMLS - Canadian Society for Medical Laboratory Science Practice Test

CSMLS - Canadian Society for Medical Laboratory Science Practice Test

CSMLS Molecular Diagnostics 3