MOLECULAR DIAGNOSTICS FINAL EXAM Q&A
What are the 5 components of PCR? - (answer)-Primers
-Taq Polymerase
-Buffer
-DNA Target
-Deoxynucleotide triphosphates (A, C, T, G)
Short synthetic oligonucleotides consisting of 20 to 30 bases in length that start the PCR reaction -
(answer)Primer
How many primers are needed for a single target? - (answer)2 (one for each strand of DNA)
How many primers are needed for multiple targets? - (answer)2 for each target
What organism is Taq polymerase isolated from? - (answer)Thermus aquaticus bacteria
What is the optimal temperature for Taq polymerase to activate? - (answer)70 degrees Celsius
What chemical component is found in PCR buffer? - (answer)Magnesium
What is the DNA target? - (answer)The DNA strand to be amplified
What temperature is the denaturation step in which the DNA is separated into individual strands? -
(answer)94 degrees Celsius
What temperature range is the annealing phase in which primers anneal to denatured DNA strands? -
(answer)55 to 65 degrees Celsius
What temperature is the elongation step in which Taq polymerase synthesizes new complementary DNA
strands? - (answer)72 degrees Celsius
,MOLECULAR DIAGNOSTICS FINAL EXAM Q&A
The target sequence _______ with each cycle. - (answer)Doubles
How many cycles does it take to perform PCR? - (answer)20 to 40
How much time does it take for one temperature cycle? - (answer)5 minutes
The original DNA strand to be amplified - (answer)Template DNA
How many sets of Template DNA are present after 20 cycles? - (answer)1
How many sets of Intermediate DNA are present after 20 cycles? - (answer)20 (1 set per cycle)
How many sets of Precise Length DNA are present after 20 cycles? - (answer)1,048,576 (2 to the 20th
exponential power)
DNA that is a product of PCR - (answer)Amplicon
To decrease the possibility of DNA cross-contamination, workflow in a molecular lab is
______________? - (answer)Uni-directional
What is the order of the workstations in a PCR lab? - (answer)Reagent station --> Extraction hood -->
PCR (Thermal Cycler & Electrophoresis machines)
Are patient samples authorized in the reagent station of a PCR lab? - (answer)No
What is the purpose of the reagent station in a PCR lab? - (answer)To prepare the master mix (primers
and Taq polymerase)
, MOLECULAR DIAGNOSTICS FINAL EXAM Q&A
To avoid contamination you should only open ___ specimen tube at a time - (answer)One
What type of micropipette tips are allowed in the PCR lab? - (answer)Aerosol Resistant Tips (ART tips)
To avoid contamination, how should reagents be handled in the PCR lab? - (answer)Aliquot large
amounts of reagent into several small containers and use the aliquot container only once (once the
container is open it must be used or disposed of; do not put it back in storage)
What cleaner is used to clean any surface that has been used to prepare a PCR sample? - (answer)Bleach
(it destroys DNA)
How often should you clean surfaces used to prepare a PCR sample? - (answer)Before, during and after
every sample
Is it okay to prepare your master mix in glassware that has been thoroughly cleansed and bleached? -
(answer)No; use disposable plasticware only
What unique centrifugation method is used in the PCR lab to prevent contamination? - (answer)Pulse
spin; it reduces the possibility of the sample becominig aerosolized in the centrifuge
To avoid contamination, what types of tubes are used in a PCR lab? - (answer)Tubes with a screwcap top
are used to avoid accidental splashing
DNA polymerase enzyme that transcribes single-stranded RNA into single-stranded DNA -
(answer)Reverse transcriptase
What is the purpose of reverse transcriptase PCR? - (answer)To convert retrovirus (Hepatitis C & HIV)
RNA into DNA that can be amplified using PCR to detect the virus and to measure gene expression
DNA synthesized from RNA by reverse transcriptase enzyme - (answer)Complementary DNA (cDNA)
What are the 5 components of PCR? - (answer)-Primers
-Taq Polymerase
-Buffer
-DNA Target
-Deoxynucleotide triphosphates (A, C, T, G)
Short synthetic oligonucleotides consisting of 20 to 30 bases in length that start the PCR reaction -
(answer)Primer
How many primers are needed for a single target? - (answer)2 (one for each strand of DNA)
How many primers are needed for multiple targets? - (answer)2 for each target
What organism is Taq polymerase isolated from? - (answer)Thermus aquaticus bacteria
What is the optimal temperature for Taq polymerase to activate? - (answer)70 degrees Celsius
What chemical component is found in PCR buffer? - (answer)Magnesium
What is the DNA target? - (answer)The DNA strand to be amplified
What temperature is the denaturation step in which the DNA is separated into individual strands? -
(answer)94 degrees Celsius
What temperature range is the annealing phase in which primers anneal to denatured DNA strands? -
(answer)55 to 65 degrees Celsius
What temperature is the elongation step in which Taq polymerase synthesizes new complementary DNA
strands? - (answer)72 degrees Celsius
,MOLECULAR DIAGNOSTICS FINAL EXAM Q&A
The target sequence _______ with each cycle. - (answer)Doubles
How many cycles does it take to perform PCR? - (answer)20 to 40
How much time does it take for one temperature cycle? - (answer)5 minutes
The original DNA strand to be amplified - (answer)Template DNA
How many sets of Template DNA are present after 20 cycles? - (answer)1
How many sets of Intermediate DNA are present after 20 cycles? - (answer)20 (1 set per cycle)
How many sets of Precise Length DNA are present after 20 cycles? - (answer)1,048,576 (2 to the 20th
exponential power)
DNA that is a product of PCR - (answer)Amplicon
To decrease the possibility of DNA cross-contamination, workflow in a molecular lab is
______________? - (answer)Uni-directional
What is the order of the workstations in a PCR lab? - (answer)Reagent station --> Extraction hood -->
PCR (Thermal Cycler & Electrophoresis machines)
Are patient samples authorized in the reagent station of a PCR lab? - (answer)No
What is the purpose of the reagent station in a PCR lab? - (answer)To prepare the master mix (primers
and Taq polymerase)
, MOLECULAR DIAGNOSTICS FINAL EXAM Q&A
To avoid contamination you should only open ___ specimen tube at a time - (answer)One
What type of micropipette tips are allowed in the PCR lab? - (answer)Aerosol Resistant Tips (ART tips)
To avoid contamination, how should reagents be handled in the PCR lab? - (answer)Aliquot large
amounts of reagent into several small containers and use the aliquot container only once (once the
container is open it must be used or disposed of; do not put it back in storage)
What cleaner is used to clean any surface that has been used to prepare a PCR sample? - (answer)Bleach
(it destroys DNA)
How often should you clean surfaces used to prepare a PCR sample? - (answer)Before, during and after
every sample
Is it okay to prepare your master mix in glassware that has been thoroughly cleansed and bleached? -
(answer)No; use disposable plasticware only
What unique centrifugation method is used in the PCR lab to prevent contamination? - (answer)Pulse
spin; it reduces the possibility of the sample becominig aerosolized in the centrifuge
To avoid contamination, what types of tubes are used in a PCR lab? - (answer)Tubes with a screwcap top
are used to avoid accidental splashing
DNA polymerase enzyme that transcribes single-stranded RNA into single-stranded DNA -
(answer)Reverse transcriptase
What is the purpose of reverse transcriptase PCR? - (answer)To convert retrovirus (Hepatitis C & HIV)
RNA into DNA that can be amplified using PCR to detect the virus and to measure gene expression
DNA synthesized from RNA by reverse transcriptase enzyme - (answer)Complementary DNA (cDNA)
