AMT MOLECULAR DIAGNOSTICS TECHNOLOGIST (MDT)
CERTIFICATION EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF
General Laboratory Principles & Safety (Q1–10)
1. When working with patient specimens in a molecular diagnostics laboratory, which
of the following practices best minimizes the risk of aerosol contamination and
cross-contamination between samples?
A. Opening all tubes simultaneously to speed up processing and reduce hands-on time
B. Using unidirectional workflow, separated pre- and post-amplification areas, and
aerosol-barrier tips
C. Reusing pipette tips between samples to reduce plastic waste and cost in the laboratory
D. Performing all steps in a single open bench area to simplify supervision and workflow
Unidirectional flow and physical separation reduce carryover of amplified material.
2. Which of the following statements best describes the primary purpose of including
a negative control in each molecular diagnostic run?
A. To confirm that the thermocycler is functioning correctly and reaching target
temperatures
B. To detect contamination or nonspecific amplification that could cause
false-positive results
C. To ensure that the extraction reagents are capable of lysing all types of microbial cells
D. To verify that the positive control has been added correctly to every reaction well
Negative controls reveal contamination or reagent-derived false positives.
3. When preparing to work with potentially infectious clinical specimens in a
molecular lab, which of the following personal protective equipment (PPE)
combinations is most appropriate for routine nucleic acid extraction?
,A. Street clothes and no gloves, since most reagents inactivate pathogens during extraction
B. Lab coat, gloves, eye protection, and optionally a face mask or shield as required
C. Only a lab coat and gloves, since molecular work does not involve any biohazard risk
D. Full positive-pressure suit with external air supply for all routine molecular procedures
Standard PPE protects against splashes and exposure to infectious material.
4. Which of the following best describes the correct interpretation of a control result
where the negative control shows amplification but the positive control and patient
samples appear normal?
A. The run is valid because the positive control amplified and patient results are clear
B. The run is invalid due to possible contamination, and results should not be
reported
C. The negative control failure can be ignored if only one well shows late amplification
D. The positive control should be repeated, but patient results can be released immediately
Any amplification in the negative control invalidates the run due to contamination risk.
5. When labeling and tracking patient specimens in a molecular diagnostics
laboratory, which of the following practices best supports accurate identification and
traceability throughout testing?
A. Using patient initials only on tubes to maintain confidentiality and reduce paperwork
B. Using at least two unique patient identifiers and barcode labels linked to the LIS
C. Relying on memory and handwritten notes to track samples during busy shifts
D. Labeling only the extraction plate and not individual tubes to save time and labels
Two identifiers and LIS-linked barcodes reduce misidentification and transcription errors.
6. Which of the following best describes the primary reason for using dedicated
pipettes and reagents in the pre-amplification area of a molecular diagnostics
laboratory?
A. To reduce the cost of purchasing high-quality pipettes for use in all areas of the lab
B. To prevent carryover of amplified nucleic acids into pre-amplification reactions
,C. To ensure that the same pipettes are calibrated identically in all laboratory areas
D. To simplify inventory management by keeping all equipment in one central location
Separate equipment and reagents prevent amplicon contamination of new reactions.
7. When performing nucleic acid quantification using spectrophotometry, which of
the following A260/A280 ratios best indicates relatively pure DNA with minimal
protein contamination?
A. Approximately 0.5, indicating high protein content and low nucleic acid purity
B. Approximately 1.8, indicating acceptable purity for most downstream molecular
applications
C. Approximately 3.0, indicating excessive protein and phenol contamination in the sample
D. Approximately 1.0, indicating equal amounts of nucleic acid and protein in the sample
An A260/A280 ratio near 1.8 is typical for pure DNA.
8. Which of the following best describes the correct action when a reagent used in a
molecular assay is found to be past its expiration date but has been stored according
to manufacturer instructions?
A. Use the reagent if it looks normal and has worked in previous runs without issues
B. Do not use the reagent and replace it with an in-date lot to ensure assay validity
C. Dilute the reagent with fresh buffer to extend its usability for non-critical controls
D. Use the reagent only for research samples and not for any patient diagnostic testing
Expired reagents are not validated and may compromise assay performance.
9. When documenting a deviation from the standard operating procedure (SOP)
during a molecular test, which of the following actions best supports quality
management and traceability?
A. Ignore the deviation if the final result appears reasonable and matches clinical
expectations
B. Record the deviation, assess impact, and follow the laboratory’s nonconformance
process
, C. Correct the record later to match the SOP so that documentation appears fully compliant
D. Report the deviation only if the final result is incorrect or flagged by quality control
Documenting and assessing deviations is essential for quality and compliance.
10. Which of the following best describes the primary purpose of performing regular
calibration and maintenance on thermocyclers and other molecular instrumentation?
A. To ensure that the laboratory meets aesthetic standards for equipment appearance and
layout
B. To verify accurate temperature control, timing, and detection for reliable assay
performance
C. To reduce the need for running controls by assuming the instrument is always functioning
D. To extend the warranty period by avoiding any service calls or manufacturer
interventions
Calibration and maintenance ensure instruments perform within specified limits.
Molecular Theory & Nucleic Acid Basics (Q11–25)
11. Which of the following best describes the structural difference between DNA and
RNA that has the greatest impact on their stability and susceptibility to degradation
in clinical specimens?
A. DNA contains uracil instead of thymine, making it more stable than RNA in most samples
B. RNA contains a 2′-hydroxyl group on the ribose, making it more prone to
hydrolysis and degradation
C. DNA is always single-stranded while RNA is always double-stranded in all biological
contexts
D. RNA contains deoxyribose instead of ribose, making it less reactive and more stable than
DNA
The 2′-OH in RNA makes it chemically less stable and more easily degraded.
12. When describing the central dogma of molecular biology, which of the following
sequences best represents the typical flow of genetic information in a eukaryotic
cell?
CERTIFICATION EXAM QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF
General Laboratory Principles & Safety (Q1–10)
1. When working with patient specimens in a molecular diagnostics laboratory, which
of the following practices best minimizes the risk of aerosol contamination and
cross-contamination between samples?
A. Opening all tubes simultaneously to speed up processing and reduce hands-on time
B. Using unidirectional workflow, separated pre- and post-amplification areas, and
aerosol-barrier tips
C. Reusing pipette tips between samples to reduce plastic waste and cost in the laboratory
D. Performing all steps in a single open bench area to simplify supervision and workflow
Unidirectional flow and physical separation reduce carryover of amplified material.
2. Which of the following statements best describes the primary purpose of including
a negative control in each molecular diagnostic run?
A. To confirm that the thermocycler is functioning correctly and reaching target
temperatures
B. To detect contamination or nonspecific amplification that could cause
false-positive results
C. To ensure that the extraction reagents are capable of lysing all types of microbial cells
D. To verify that the positive control has been added correctly to every reaction well
Negative controls reveal contamination or reagent-derived false positives.
3. When preparing to work with potentially infectious clinical specimens in a
molecular lab, which of the following personal protective equipment (PPE)
combinations is most appropriate for routine nucleic acid extraction?
,A. Street clothes and no gloves, since most reagents inactivate pathogens during extraction
B. Lab coat, gloves, eye protection, and optionally a face mask or shield as required
C. Only a lab coat and gloves, since molecular work does not involve any biohazard risk
D. Full positive-pressure suit with external air supply for all routine molecular procedures
Standard PPE protects against splashes and exposure to infectious material.
4. Which of the following best describes the correct interpretation of a control result
where the negative control shows amplification but the positive control and patient
samples appear normal?
A. The run is valid because the positive control amplified and patient results are clear
B. The run is invalid due to possible contamination, and results should not be
reported
C. The negative control failure can be ignored if only one well shows late amplification
D. The positive control should be repeated, but patient results can be released immediately
Any amplification in the negative control invalidates the run due to contamination risk.
5. When labeling and tracking patient specimens in a molecular diagnostics
laboratory, which of the following practices best supports accurate identification and
traceability throughout testing?
A. Using patient initials only on tubes to maintain confidentiality and reduce paperwork
B. Using at least two unique patient identifiers and barcode labels linked to the LIS
C. Relying on memory and handwritten notes to track samples during busy shifts
D. Labeling only the extraction plate and not individual tubes to save time and labels
Two identifiers and LIS-linked barcodes reduce misidentification and transcription errors.
6. Which of the following best describes the primary reason for using dedicated
pipettes and reagents in the pre-amplification area of a molecular diagnostics
laboratory?
A. To reduce the cost of purchasing high-quality pipettes for use in all areas of the lab
B. To prevent carryover of amplified nucleic acids into pre-amplification reactions
,C. To ensure that the same pipettes are calibrated identically in all laboratory areas
D. To simplify inventory management by keeping all equipment in one central location
Separate equipment and reagents prevent amplicon contamination of new reactions.
7. When performing nucleic acid quantification using spectrophotometry, which of
the following A260/A280 ratios best indicates relatively pure DNA with minimal
protein contamination?
A. Approximately 0.5, indicating high protein content and low nucleic acid purity
B. Approximately 1.8, indicating acceptable purity for most downstream molecular
applications
C. Approximately 3.0, indicating excessive protein and phenol contamination in the sample
D. Approximately 1.0, indicating equal amounts of nucleic acid and protein in the sample
An A260/A280 ratio near 1.8 is typical for pure DNA.
8. Which of the following best describes the correct action when a reagent used in a
molecular assay is found to be past its expiration date but has been stored according
to manufacturer instructions?
A. Use the reagent if it looks normal and has worked in previous runs without issues
B. Do not use the reagent and replace it with an in-date lot to ensure assay validity
C. Dilute the reagent with fresh buffer to extend its usability for non-critical controls
D. Use the reagent only for research samples and not for any patient diagnostic testing
Expired reagents are not validated and may compromise assay performance.
9. When documenting a deviation from the standard operating procedure (SOP)
during a molecular test, which of the following actions best supports quality
management and traceability?
A. Ignore the deviation if the final result appears reasonable and matches clinical
expectations
B. Record the deviation, assess impact, and follow the laboratory’s nonconformance
process
, C. Correct the record later to match the SOP so that documentation appears fully compliant
D. Report the deviation only if the final result is incorrect or flagged by quality control
Documenting and assessing deviations is essential for quality and compliance.
10. Which of the following best describes the primary purpose of performing regular
calibration and maintenance on thermocyclers and other molecular instrumentation?
A. To ensure that the laboratory meets aesthetic standards for equipment appearance and
layout
B. To verify accurate temperature control, timing, and detection for reliable assay
performance
C. To reduce the need for running controls by assuming the instrument is always functioning
D. To extend the warranty period by avoiding any service calls or manufacturer
interventions
Calibration and maintenance ensure instruments perform within specified limits.
Molecular Theory & Nucleic Acid Basics (Q11–25)
11. Which of the following best describes the structural difference between DNA and
RNA that has the greatest impact on their stability and susceptibility to degradation
in clinical specimens?
A. DNA contains uracil instead of thymine, making it more stable than RNA in most samples
B. RNA contains a 2′-hydroxyl group on the ribose, making it more prone to
hydrolysis and degradation
C. DNA is always single-stranded while RNA is always double-stranded in all biological
contexts
D. RNA contains deoxyribose instead of ribose, making it less reactive and more stable than
DNA
The 2′-OH in RNA makes it chemically less stable and more easily degraded.
12. When describing the central dogma of molecular biology, which of the following
sequences best represents the typical flow of genetic information in a eukaryotic
cell?
