AAB Molecular Diagnostics Exam
2025 With 100% Correct Answers
This DNA amplification method amplifies the nucleic acid used as a probe? - CORRECT
ANSWER✔✔Ligase Chain Reaction (LCR)
What enzymes are used in Ligase Chain Reactions? - CORRECT ANSWER✔✔DNA polymerase
and DNA ligase
What is the function of DNA polymerase in Ligase Chain Reaction? - CORRECT ANSWER✔✔Is
used to initiate DNA polymerase.
What is the key advantage of using Ligase Chain Reaction instead of Polymerase Chain Reaction?
- CORRECT ANSWER✔✔Better specificity
How does Ligase Chain Reaction differ from Polymerase Chain Reaction? - CORRECT
ANSWER✔✔This method uses a thermostable ligase to join to probes which are then amplified
by standard PCR cycling.
Why was Ligase Chain Reaction originally developed? - CORRECT ANSWER✔✔To detect point
mutation.
What do positive controls ensure during PCR testing? - CORRECT ANSWER✔✔That the enzyme
is active, the buffer is optimal, the primers are priming the correct sequence, and that the
thermal cycler is working properly.
, What is a reagent blank control in PCR? - CORRECT ANSWER✔✔A negative control that lacks
DNA to ensure that the reaction mix is not contaminated with DNA template or amplified
products from a previous run.
What is a negative template control in PCR? - CORRECT ANSWER✔✔A negative control that
contains DNA that lacks this target DNA sequence. This ensures that the primers are not
annealing to unintended DNA sequences.
What is the purpose of the amplification control in PCR? - CORRECT ANSWER✔✔To distinguish
between a true negative for the sample and an amplification failure (false negative).
What is the major source of contamination in PCR testing? - CORRECT ANSWER✔✔Amplicons
from previous runs.
What is a method for removing nucleotides and primers from PCR products prior to
sequencing? - CORRECT ANSWER✔✔Shrimp alkaline phosphatase (SAP) and exonuclease I
(ExoI)
How does nested PCR increase both specificity and sensitivity? - CORRECT ANSWER✔✔By using
two pairs of primers to amplify a single target in two separate PCR runs. The second pair of
primers bind slightly inside the binding sites of the first pair. This will increase the intended PCR
product.
How does PCR differ from qPCR (real time)? - CORRECT ANSWER✔✔PCR detects the final
product by endpoint analysis.
How does qPCR differ from PCR? - CORRECT ANSWER✔✔qPCR detects the quantity of product
as it is produced during the run.
What is the purpose of the quencher in qPCR? - CORRECT ANSWER✔✔To reduce the
florescence signal.
2025 With 100% Correct Answers
This DNA amplification method amplifies the nucleic acid used as a probe? - CORRECT
ANSWER✔✔Ligase Chain Reaction (LCR)
What enzymes are used in Ligase Chain Reactions? - CORRECT ANSWER✔✔DNA polymerase
and DNA ligase
What is the function of DNA polymerase in Ligase Chain Reaction? - CORRECT ANSWER✔✔Is
used to initiate DNA polymerase.
What is the key advantage of using Ligase Chain Reaction instead of Polymerase Chain Reaction?
- CORRECT ANSWER✔✔Better specificity
How does Ligase Chain Reaction differ from Polymerase Chain Reaction? - CORRECT
ANSWER✔✔This method uses a thermostable ligase to join to probes which are then amplified
by standard PCR cycling.
Why was Ligase Chain Reaction originally developed? - CORRECT ANSWER✔✔To detect point
mutation.
What do positive controls ensure during PCR testing? - CORRECT ANSWER✔✔That the enzyme
is active, the buffer is optimal, the primers are priming the correct sequence, and that the
thermal cycler is working properly.
, What is a reagent blank control in PCR? - CORRECT ANSWER✔✔A negative control that lacks
DNA to ensure that the reaction mix is not contaminated with DNA template or amplified
products from a previous run.
What is a negative template control in PCR? - CORRECT ANSWER✔✔A negative control that
contains DNA that lacks this target DNA sequence. This ensures that the primers are not
annealing to unintended DNA sequences.
What is the purpose of the amplification control in PCR? - CORRECT ANSWER✔✔To distinguish
between a true negative for the sample and an amplification failure (false negative).
What is the major source of contamination in PCR testing? - CORRECT ANSWER✔✔Amplicons
from previous runs.
What is a method for removing nucleotides and primers from PCR products prior to
sequencing? - CORRECT ANSWER✔✔Shrimp alkaline phosphatase (SAP) and exonuclease I
(ExoI)
How does nested PCR increase both specificity and sensitivity? - CORRECT ANSWER✔✔By using
two pairs of primers to amplify a single target in two separate PCR runs. The second pair of
primers bind slightly inside the binding sites of the first pair. This will increase the intended PCR
product.
How does PCR differ from qPCR (real time)? - CORRECT ANSWER✔✔PCR detects the final
product by endpoint analysis.
How does qPCR differ from PCR? - CORRECT ANSWER✔✔qPCR detects the quantity of product
as it is produced during the run.
What is the purpose of the quencher in qPCR? - CORRECT ANSWER✔✔To reduce the
florescence signal.
