Molecular Diagnostic Testing

Question 1

What is the purpose of molecular diagnostic testing?

Answer 1

The ability to detect specific nucleic acid sequences in microorganisms or cells before antibody detection.

Question 2

Define purine bases.

Answer 2

Adenine and guanine.

Question 3

Define pyrimidine bases.

Answer 3

Cytosine and thymine.

Question 4

What is the role of RNA in protein production?

Answer 4

Helps convert genetic information within DNA into proteins.

Question 5

Pyrimidine bases in RNA contains ___ instead of thymine.

Answer 5

uracil.

Question 6

Nucleosides contain…

Answer 6

Carbohydrate + base.

Question 7

Nucleotides contain…

Answer 7

Phosphate + carbohydrate + base.

Question 8

What is the complementary base for adenine in DNA?

Answer 8

Thymine.

Question 9

What is the complementary base for guanine in DNA?

Answer 9

Cytosine.

Question 10

What is the complementary base for adenine in RNA?

Answer 10

Uracil.

Question 11

In what direction is the DNA read during the replication process?

Answer 11

5’ to 3’.

Question 12

What enzyme is needed for synthesis of DNA?

Answer 12

DNA polymerase.

Question 13

What is the role of DNA helicase?

Answer 13

Breaks up complementary pairs.

Question 14

RNA synthesis is catalyzed by what enzyme?

Answer 14

RNA polymerase.

Question 15

RNA codes for…

Answer 15

Proteins, tRNA, rRNA, long and short noncoding RNA.

Question 16

Describe a conservative substitution mutation.

Answer 16

Nucleotide base substitution that results in an amino acid with similar properties as compared with the original.

Question 17

Describe a nonconservative substitution mutation.

Answer 17

Nucleotide base substitution that results in an amino acid with dissimilar properties as compared with the original.

Question 18

Describe a silent mutation.

Answer 18

Nucleotide base substitution that results in the same amino acid.

Question 19

Describe a nonsense mutation.

Answer 19

Nucleotide base substitution that results in the creation of a stop codon.

Question 20

Describe a frameshift mutation.

Answer 20

Insertion or deletion of a nucleotide base that causes a shift in the codon reading frame.

Question 21

Define polymorphism.

Answer 21

Similar to a mutation or variant, but defined by frequency within a population (i.e., sickle cell anemia).

Question 22

Describe the strand cleavage method of molecular diagnostics.

Answer 22

Cleaves DNA at specific locations; used to investigate small genomes and detect mutations and polymorphisms.

Question 23

Define hybridization.

Answer 23

Binding two complementary strands on nucleic acids.

Question 24

Southern Blot analysis is used to assess what?

Answer 24

Specific DNA sequences.

Question 25

What is the procedure of a Southern Blot analysis?

Answer 25

Restriction enzymes cleave DNA into small fragments which are separated through gel electrophoresis. The regions are identified through hybridization with labeled probes.

Question 26

Western Blot analysis is used to assess what?

Answer 26

Proteins that are separated through gel electrophoresis.

Question 27

The array method of hybridization uses ___ and can be run at the same time.

Answer 27

multiple targets or samples.

Question 28

What hybridization method would be best for leukemia prognosis, or the diagnosis of an autoimmune condition?

Answer 28

An array method.

Question 29

Bead arrays uses ___ detection of proteins and nucleic acids. The beads have ___ or single-stranded oligonucleotides attached.

Answer 29

multiplex; antibodies.

Question 30

The bead array method is good for what types of testing?

Answer 30

Respiratory virus panels.

Question 31

What does florescence in situ hybridization (FISH) used to detect?

Answer 31

Chromosome abnormalities, T-cell lymphomas, B-cell malignancies, and graft-versus-host disease.

Question 32

What is the process of florescence in situ hybridization (FISH)?

Answer 32

Cells or thin tissue sections are deposited on a glass slide. Probes are then covalently attached to fluorescent dye to view hybridization.

Question 33

The most frequent method used in molecular diagnostics is…

Answer 33

Amplification methods.

Question 34

Define amplification.

Answer 34

Copying nucleic acids to obtain enough for identification (e.g., PCR testing).

Question 35

Transcription-based amplification methods uses isothermal amplification methods and is different from PCR because…

Answer 35

It doesn’t require thermocycling.

Question 36

What is the principle behind the ligase chain reaction?

Answer 36

Amplifies probes rather than target DNA. Two primers are attached to the target DNA sequence and then the primers are joined and amplified.

Question 37

Define ligase.

Answer 37

An enzyme that joins two DNA chains by creating phosphodiester bonds.

Question 38

Describe the Sanger (chain termination) DNA sequencing method.

Answer 38

DNA replication that uses fluorescent-label ddNTPs.

Question 39

Describe the pyrosequencing DNA sequencing method.

Answer 39

Generation of light when nucleotides are added to a growing strand of DNA.