PCR PCR Applications & Clinical Diagnostics 1 — Questions and Answers
Question 1: Which PCR application is most commonly used in US clinical laboratories to detect SARS-CoV-2?
- RT-PCR (reverse transcription PCR) (Correct answer)
- Standard endpoint PCR
- Allele-specific PCR
- Inverse PCR
Correct answer: RT-PCR (reverse transcription PCR)
RT-PCR is used to detect SARS-CoV-2 because the virus has an RNA genome that must first be reverse-transcribed into cDNA before amplification.
Question 2: In oncology diagnostics, which PCR-based method is used to detect minimal residual disease (MRD) in leukemia patients?
- Quantitative real-time PCR (qPCR) (Correct answer)
- Nested PCR
- Colony PCR
- Asymmetric PCR
Correct answer: Quantitative real-time PCR (qPCR)
qPCR is used for MRD detection because it can quantify extremely low levels of residual leukemic cells with high sensitivity.
Question 3: Which PCR technique is used to identify single nucleotide polymorphisms (SNPs) associated with drug metabolism in pharmacogenomics?
- Allele-specific PCR (Correct answer)
- Long-range PCR
- Inverse PCR
- Ligation-mediated PCR
Correct answer: Allele-specific PCR
Allele-specific PCR uses primers designed to amplify only one allele, making it ideal for distinguishing SNP variants relevant to pharmacogenomics.
Question 4: In forensic DNA analysis in the US, which PCR-based technique is used to generate a DNA profile for identity comparison?
- STR (Short Tandem Repeat) PCR analysis (Correct answer)
- Digital PCR
- Multiplex ligation-dependent probe amplification
- Restriction fragment length polymorphism
Correct answer: STR (Short Tandem Repeat) PCR analysis
STR PCR analysis amplifies multiple short tandem repeat loci simultaneously to generate a DNA profile used by CODIS for identity matching.
Question 5: Which PCR application is used to diagnose genetic disorders prenatally by analyzing cell-free fetal DNA in maternal blood?
- Non-invasive prenatal testing (NIPT) using qPCR (Correct answer)
- In situ PCR
- Hot-start PCR
- Reverse complement PCR
Correct answer: Non-invasive prenatal testing (NIPT) using qPCR
NIPT uses qPCR or next-generation sequencing on cell-free fetal DNA circulating in maternal plasma to detect chromosomal abnormalities.
Question 6: For food safety testing in the US, which PCR method allows detection of multiple pathogens such as Salmonella and E. coli simultaneously in a single reaction?
- Multiplex PCR (Correct answer)
- Touch-down PCR
- Booster PCR
- Isothermal PCR
Correct answer: Multiplex PCR
Multiplex PCR uses multiple primer pairs in one reaction tube to detect several pathogens simultaneously, making food safety screening faster and more cost-effective.
PCR PCR Applications & Clinical Diagnostics 1
Which PCR application is most commonly used in US clinical laboratories to detect SARS-CoV-2?