MOLECULAR DIAGNOSTICS EXAM
REVIEW QUESTIONS AND ANSWERS
What helps to visualize the sample while electrophoresis is taking place? -
ANSWER-Loading dye (buffer)
What types of loading dyes are available? - ANSWER--Ethidium bromide
(carcinogenic)
-Fast Blast
What are the contents of the loading dye? - ANSWER--10 to 20% glycerol
-Tracking dye
Polyacrylamide Gel Electrophoresis - ANSWER-PAGE
PAGE composition: - ANSWER-Cross-linked polyacrylamide polymer
PAGE pore uniformity: - ANSWER-More uniform than agarose gel
Is PAGE toxic? - ANSWER-Yes, PAGE is a neurotoxin
PAGE advantage: - ANSWER-Can distinguish between small fragments up to 1
base pair difference
PAGe disadvantage: - ANSWER-Need large glass plates (gel is poured between the
plates)
Used to separate very large DNA fragments - ANSWER-Pulse Field Gel
Electrophoresis
Using PFGE, what do you need to do to get a better separation of the fragments? -
ANSWER-Precisely change direction of electrical current
Is PFGE current modulation a manual or automated process? - ANSWER-
Automated
Network of local, state, and federal agencies that run DNA sequencing on food-
borne disease-causing bacteria - ANSWER-PulseNet
Which organisms are in the PulseNet database? - ANSWER--E. coli O157:H7
-Salmonella
-Shigella
-Listeria
-Campylobacter
-Vibrio cholerae
, What is the goal of the PulseNet database? - ANSWER-Rapidly detect outbreaks of
food-borne diseases & take preventive action
Used to determine the exact nucleotide composition of a DNA fragment - ANSWER-
DNA Sequencing
Applications of DNA Sequencing include: - ANSWER--HIV & HCV genotyping
(determine resistance to anti-retroviral drugs)
-Forensics (identity testing)
-Human Genome Project
What is the difference between deoxyribose and di-deoxyribose? - ANSWER-
Deoxyribose has an OH group at the third carbon position (Di-deoxyribose only has
an H)
What is the significance of the change to the third carbon position? - ANSWER-Key
component that is critical for chain termination
ddATP fluorescent color? - ANSWER-Green
ddTTP fluorescent color? - ANSWER-Red
ddCTP fluorescent color? - ANSWER-Blue
ddGTP fluorescent color? - ANSWER-Yellow
True or False: There is only a small amount of di-deoxynucleotides mixed in with the
DNA. - ANSWER-True
What is used to determine the DNA sequence using di-deoxynucleotides? -
ANSWER-Electrophoresis
Formation of stable double stranded nucleic acid structure due to complementary
base pairing and the formation of hydrogen bonding - ANSWER-DNA Hybridization
Possible hybrids include: - ANSWER--DNA/DNA
-RNA/RNA
-DNA/RNA
DNA or RNA fragment used to detect specific DNA or RNA in mixture - ANSWER-
Probe
Probe composition - ANSWER-Single-stranded oligonucleotide (complementary) to
region of interest
Which hybridization-based molecular techniques ("blots") are available: - ANSWER--
Southern Blot
-Northern Blot
-Western Blot
-FISH (Flourescent in situ hybridization)
REVIEW QUESTIONS AND ANSWERS
What helps to visualize the sample while electrophoresis is taking place? -
ANSWER-Loading dye (buffer)
What types of loading dyes are available? - ANSWER--Ethidium bromide
(carcinogenic)
-Fast Blast
What are the contents of the loading dye? - ANSWER--10 to 20% glycerol
-Tracking dye
Polyacrylamide Gel Electrophoresis - ANSWER-PAGE
PAGE composition: - ANSWER-Cross-linked polyacrylamide polymer
PAGE pore uniformity: - ANSWER-More uniform than agarose gel
Is PAGE toxic? - ANSWER-Yes, PAGE is a neurotoxin
PAGE advantage: - ANSWER-Can distinguish between small fragments up to 1
base pair difference
PAGe disadvantage: - ANSWER-Need large glass plates (gel is poured between the
plates)
Used to separate very large DNA fragments - ANSWER-Pulse Field Gel
Electrophoresis
Using PFGE, what do you need to do to get a better separation of the fragments? -
ANSWER-Precisely change direction of electrical current
Is PFGE current modulation a manual or automated process? - ANSWER-
Automated
Network of local, state, and federal agencies that run DNA sequencing on food-
borne disease-causing bacteria - ANSWER-PulseNet
Which organisms are in the PulseNet database? - ANSWER--E. coli O157:H7
-Salmonella
-Shigella
-Listeria
-Campylobacter
-Vibrio cholerae
, What is the goal of the PulseNet database? - ANSWER-Rapidly detect outbreaks of
food-borne diseases & take preventive action
Used to determine the exact nucleotide composition of a DNA fragment - ANSWER-
DNA Sequencing
Applications of DNA Sequencing include: - ANSWER--HIV & HCV genotyping
(determine resistance to anti-retroviral drugs)
-Forensics (identity testing)
-Human Genome Project
What is the difference between deoxyribose and di-deoxyribose? - ANSWER-
Deoxyribose has an OH group at the third carbon position (Di-deoxyribose only has
an H)
What is the significance of the change to the third carbon position? - ANSWER-Key
component that is critical for chain termination
ddATP fluorescent color? - ANSWER-Green
ddTTP fluorescent color? - ANSWER-Red
ddCTP fluorescent color? - ANSWER-Blue
ddGTP fluorescent color? - ANSWER-Yellow
True or False: There is only a small amount of di-deoxynucleotides mixed in with the
DNA. - ANSWER-True
What is used to determine the DNA sequence using di-deoxynucleotides? -
ANSWER-Electrophoresis
Formation of stable double stranded nucleic acid structure due to complementary
base pairing and the formation of hydrogen bonding - ANSWER-DNA Hybridization
Possible hybrids include: - ANSWER--DNA/DNA
-RNA/RNA
-DNA/RNA
DNA or RNA fragment used to detect specific DNA or RNA in mixture - ANSWER-
Probe
Probe composition - ANSWER-Single-stranded oligonucleotide (complementary) to
region of interest
Which hybridization-based molecular techniques ("blots") are available: - ANSWER--
Southern Blot
-Northern Blot
-Western Blot
-FISH (Flourescent in situ hybridization)
