MOLECULAR DIAGNOSTICS FINAL
EXAM (INCLUDES MATERIAL FROM
EXAMS 3 & 4) WITH COMPLETE
SOLUTIONS
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
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
DNA synthesized from RNA by reverse transcriptase enzyme - ANSWER-
Complementary DNA (cDNA)
Genomic DNA has both introns and exons. Does cDNA also have introns and exons? -
ANSWER-cDNA only has exons; cDNA is synthesized from mRNA, therefore there are
no introns
What primer is necessary for the reverse transcriptase enzyme to transcribe RNA into
cDNA for the purpose of measuring gene expression? Why is it necessary? - ANSWER-
poly(T) oligonucleotide primer; poly(T) binds to the poly(A) tail of mRNA and reverse
transcriptase binds to the poly(T)
What primer is necessary for the reverse transcriptase enzyme to transcribe RNA into
cDNA for the purpose of viral identification? - ANSWER-Sequence specific primers
Amplification of 2 or more target sequences in one reaction? - ANSWER-Multiplex PCR
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)
To avoid contamination you should only open ___ specimen tube at a time - ANSWER-
One
EXAM (INCLUDES MATERIAL FROM
EXAMS 3 & 4) WITH COMPLETE
SOLUTIONS
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
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
DNA synthesized from RNA by reverse transcriptase enzyme - ANSWER-
Complementary DNA (cDNA)
Genomic DNA has both introns and exons. Does cDNA also have introns and exons? -
ANSWER-cDNA only has exons; cDNA is synthesized from mRNA, therefore there are
no introns
What primer is necessary for the reverse transcriptase enzyme to transcribe RNA into
cDNA for the purpose of measuring gene expression? Why is it necessary? - ANSWER-
poly(T) oligonucleotide primer; poly(T) binds to the poly(A) tail of mRNA and reverse
transcriptase binds to the poly(T)
What primer is necessary for the reverse transcriptase enzyme to transcribe RNA into
cDNA for the purpose of viral identification? - ANSWER-Sequence specific primers
Amplification of 2 or more target sequences in one reaction? - ANSWER-Multiplex PCR
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)
To avoid contamination you should only open ___ specimen tube at a time - ANSWER-
One
