Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Diagnostic Molecular Biology > Quiz #2,3 > Flashcards

Quiz #2,3 Flashcards

1
Q

Which of the following is the first step in DNA isolation from cells in a clinical sample?

a. DNA precipitation
b. Precipitation of proteins
c. Lysis of cells
d. Eluting DNA from a spin column

A

c. Lysis of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Phenol/chloroform in an aqueous solution will form what type of mixture?

a. Simple solution
b. Emulsion
c. Suspension
d. Supersaturated solution

A

b. Emulsion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In organic DNA extraction methods, the DNA is found in which fraction?

a. Upper aqueous
b. Lower aqueous
c. Upper hydrophobic
d. Lower hydrophobic

A

a. Upper aqueous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

DNA, after separation from other cellular constituents, is precipitated in which of the following?

a. Chloroform
b. Isopropanol
c. Ethylenediaminetetraacetic acid
d. Sodium dodecyl sulfate

A

b. Isopropanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The most abundant form of RNA in all cells is

a. Ribosomal
b. Transfer
c. Messenger
d. Small nuclear

A

a. Ribosomal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Diethyl pyrocarbonate (DEPC) is a chemical that is used to

a. Inactivate DNases
b. Measure DNA concentration
c. Isolate mitochondria
d. Inactivate RNases

A

d. Inactivate RNases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In organic isolation of RNA procedures, guanidinium isothiocyanate is added to

a. Degrade DNA
b. Denature all proteins
c. Inhibit RNases
d. Separate RNA from DNA

A

c. Inhibit RNases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

PolyT oligomers bound to a matrix resin column will selectively isolate which of the following?

a. Ribosomal RNA
b. GC-rich DNA
c. Transfer RNA
d. Messenger RNA

A

d. Messenger RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nucleic acid concentration can be assessed relatively simply and quickly by which of the following procedures?

a. Electrophoresis
b. Enzyme immunoassay
c. Sequencing
d. Spectrophotometry at 2600 nm

A

a. Electrophoresis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the concentration of DNA whereby a 1:100 dilution has an observance reading of 0.015 at 260 nm?

a. 6 μg/mL
b. 60 μg/mL
c. 75 μg/mL
d. 750 μg/mL

A
  1. 015 * 50 * 100

c. 75 μg/mL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the yield of DNA from a sample with concentration of 280 micrograms/mL and a volume of 0.5 mL?

a. 70 μg
b. 140 μg
c. 280 μg
d. 560 μg

A

b. 140 μg

FINISH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When measuring the concentration of RNA by spectrophotometry at 260 nm, the absorbance reading is multiplied by the dilution and a conversion factor of

a. 20
b. 30
c. 40
d. 50

A

c. 40

FINISH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the concentration of RNA whereby a 1:10 dilution has an absorbance reading of 0.675 at 260 nm?

a. 33.75 μg/mL
b. 337.5 μg/mL
c. 27 μg/mL
d. 270 μg/mL

A

d. 270 μg/mL

FINISH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the yield of RNA from the sample with concentration of 450 micrograms/mL and a volume of 0.3 mL?

a. 135 μg
b. 150 μg
c. 225 μg
d. 450 μg

A

a. 135 μg

FINISH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

DNA is isolated from a clinical sample. The absorbance at 260 nm is 0.489, and the absorbance at 280 nm is 0.257. Is this sample of sufficient quality for use in subsequent analysis?

a. Yes
b. No
c. Cannot be determined with the given data.

A

a. Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A DNA-specific dye that is used in fluorometry procedures to measure DNA concentration is

a. EtBr
b. Diethyl pyrocarbonate
c. SYBR Green
d. Hoechst 33258

A

b. Diethyl pyrocarbonate

17
Q

In what way is fluorometry more accurate than spectrophotometry?

a. Fluorescence is more specific for single nucleotides
b. Spectrophotometry only measures absorbance from intact nucleic acid polymers
c. Using specific stains, fluorometry only detects intact dsDNA
d. Absorbance may require dilution of sample before reading

A

c. Using specific stains, fluorometry only detects intact dsDNA

18
Q

Which of the following molecules polymerize to for a support medium through which nucleic acids move?

a. EtBr
b. Ethylenediaminetetraacetic acid
c. Sodium dodecyl sulfate
d. Polyacrylamide

A

d. Polyacrylamide

19
Q

The positive pole in electrophoresis is indicated by which color?

a. Red
b. Black
c. Green
d. White

A

a. Red

20
Q

Nucleic acids migrate toward which pole in electrophoresis?

a. Cathode
b. Anode
c. Both
d. Neither

A

b. Anode

21
Q

What concentration of agarose should be used for optimal separation of DNA fragments of 100, 250, and 350 bp in length?

a. 0.5%
b. 0.7%
c. 2.0%
d. 12.0%

A

c. 2.0%

22
Q

How does one prepare a 2% agarose gel?

a. Mix 0.01 g agarose/mL running buffer and heat
b. Mix 0.02 g agarose/mL running buffer and heat
c. Mix 2 g agarose/mL running buffer and heat
d. Mix 1 g agarose/mL running buffer and heat

A

b. Mix 0.02 g agarose/mL running buffer and heat

23
Q

What is one reason that polyacrylamide gels have higher resolution than agarose els for small fragments?

a. Agarose polymer spaces are bigger than those of polyacrylamide
b. Agarose polymers are very fragile
c. Agarose won’t separate molecules over a certain size
d. Agarose is a synthetic polymer in which sieving properties can be precisely controlled

A

a. Agarose polymer spaces are bigger than those of polyacrylamide

24
Q

What is an advantage of agarose over polyacrylamide gels?

a. Agarose is more stable than pa
b. Agarose monomer are not toxic
c. Acrylamide takes a long time to polymerize
d. Polyacrylamide gels must be used immediately after polymerization

A

b. Agarose monomer are not toxic

25
Q

To separate a mixture of oligonucleotides with a resolution between bands of 1 bp, which of the following methods should be used?

a. Contour-clamped homogenous electric field
b. Rotating fel electrophoresis
c. Polyacrylamide gel electrophoresis
d. Traditional gel electrophoresis

A

c. Polyacrylamide gel electrophoresis

26
Q

Which of the following molecules is added to an electrophoresis buffer for the purpose of denaturing DNA?

a. Ethylenediaminetetraacetic acid
b. Polyacrylamide
c. Formamide
d. Tris borate

A

c. Formamide

27
Q

To increase the density of a sample relative to the density of the buffer prior to loading the sample into a gel, which of the following is added to the sample?

a. Glycerol
b. EtBr
c. Formaldehyde
d. Tris acetate EDTA

A

a. Glycerol

28
Q

A molecular technologist has run a vertical get. While analyzing the gel, the technologist notices that the bands in the outer lanes did not run as far as similar-sized bands in the inner lanes, so the bands looked like a smile on the gel. What is the explanation for this?

a. Samples were loaded into the inner wells first and got a head start moving down the gel
b. A larger volume of sample was loaded into the outer wells so that they ran slower
c. The electrodes in the middle of the gel were working better than at the edges of the gel
d. The temperature across the gel was not constant, so the inner wells were warmer

A

d. The temperature across the gel was not constant, so the inner wells were warmer

29
Q

To monitor the progress of electrophoresis, which of the following is added to a sample that does not associate with DNA and runs ahead of the smallest fragments in the sample?

a. EtBr
b. Acrylamide
c. Bromophenol blue
d. SYBR Green

A

c. Bromophenol blue

30
Q

Which is an important property of gel running buffers?

a. Solubility at low temperature
b. Ability to maintain constant pH
c. Capacity to heat up quickly
d. High UV light absorption

A

b. Ability to maintain constant pH

31
Q

The functions of which of the following include carrying the current and protecting the sample nucleic acids during electrophoresis?

a. Glycerol
b. Formamide
c. Ammonium per sulfate
d. Tris borate EDTA

A

d. Tris borate EDTA

32
Q

A CIRCULAR molecule has two sites for the restriction enzyme PstI and one site for the enzyme ManHI. How many fragments will result when digested with both enzymes?

a. 1
b. 2
c. 3
d. 4

A

c. 3

33
Q

A LINEAR molecule has two sites for the restriction enzyme PstI and one site for the enzyme ManHI. How many fragments will result when digested with both enzymes?

a. 1
b. 2
c. 3
d. 4

A

d. 4

34
Q

What is learned from the size of restriction fragments as determined by migration speed in gel electrophoresis?

a. The specificity of the restriction enzyme
b. The distance between restriction enzyme recognition sites
c. The rate of digestion of the enzyme
d. The number of restriction sites in the DNA

A

b. The distance between restriction enzyme recognition sites

35
Q

What is star activity?

a. Optimal specific activity of a restriction enzyme
b. Nonspecific digestion of DNA by a restriction enzyme
c. Degradation of DNA ends
d. Re-ligation of cut DNA

A

b. Nonspecific digestion of DNA by a restriction enzyme

36
Q

A 6% solution of 19:1 acrylamide is mixed and pouted between the glass plates for gel formation. But, after an hour the solution is still liquid. What might be one explanation for the gel not polymerizing?

A

The polymerizing catalyst or the nucleating agent was not added

37
Q

A gel separation of RNA yields aberrantly migrating bands and smears. Suggest two possible explanation for this observation.

A
  1. The RNA was degraded

2. The gel conditions were improper for the RNA sample

38
Q

I just isolated total RNA from brain tissues. Now, I want to isolate mRNA from this total RTNA. (Hint: What’s so unique about mRNA that allows mw to isolate it?)

A

Use a bead with a PolyT or PolyU oligomer, which will attach to the PolyA tail of the mRNA

39
Q

For transformation of a plasmid DNA into competent bacterial cells, what two factors allows for efficient transformation?

A
  1. CaCl2

2. Heat shock

Diagnostic Molecular Biology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions