Chapter 11: Molecular Techniques Flashcards

1
Q

What represents a significant advancement in clinical microbiology?

A

Molecular Diagnostics

Considered the fastest growing section in many clinical laboratories.

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

What do molecular diagnostics provide to clinicians?

A

Rapid answers for treatment options

Saves valuable time in cases of life-threatening infections.

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

When are molecular techniques particularly useful?

A

When traditional methods are not practical or available.

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

Which organisms cannot be routinely cultivated?

A

Viruses and Chlamydia

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

What is required for the growth of Mycobacterium tuberculosis?

A

A long incubation period

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

What are genetic probes?

A

Short, specific sequences of single-stranded DNA or RNA

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

What do genetic probes identify within nucleic acid?

A

One or more sequences of interest

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

What does the degree of hybridization depend on?

A

Base sequence homology and reaction conditions

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

What are the conditions that affect stringency?

A

Length of probe, probe concentration, degree of complementarity, salt concentration, temperature, pH, concentration of destabilizing agents

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

What determines the detection of hybridization?

A

Type of label

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

What is the most common method for detection in clinical microbiology?

A

Chemiluminescence

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

List the formats of nucleic acid probes.

A
  • Liquid phase
  • Solid phase
  • Southern blot
  • Northern blot
  • In situ hybridization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is signal amplification in nucleic acid amplification methods?

A

Increased concentration of labeled molecule without increasing probe or target concentration.

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

Branched DNA amplification:

A

Solid phase sandwich hybridization that uses multiple sets of synthetic probes

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

Hybris capture assays:

A

Solution hybridization antibody capture

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

Target amplification:

A

– Enzymes produce copies of target nucleic acid which are detected by primers that bind to complementary strands.

– Produces millions of copies of targeted sequence which act as templates for subsequent amplification cycles.

– Polymerase chain reaction (PCR)

17
Q

What is the purpose of Polymerase Chain Reaction (PCR)?

A

To produce millions of copies of targeted nucleic acid sequence

18
Q

What is the first step in the Polymerase Chain Reaction?

A

Denature nucleic acid into single stranded DNA

19
Q

What is Reverse Transcriptase PCR (RT-PCR) used for?

A

To detect RNA viruses

20
Q

What does Nucleic Acid Sequence-Based Amplification (NASBA) require?

A

Three enzymes: AMV reverse transcriptase, Ribonuclease H, T7 RNA polymerase

Target could be DNA or RNA most often RNA viruses

21
Q

What is Transcription-Mediated Amplification (TMA) developed for?

A

Detection of C. trachomatis and N. gonorrhoeae

Targets rRNA

22
Q

What is strain typing and identification based on?

A

DNA or genetic fingerprinting and genetic relatedness

23
Q

What are Amplification Independent Methods?

A
  • Restriction Fragment Length Polymorphisms (RFLPs)
  • Southern blotting
  • Plasmid profile analysis
  • Multilocus enzyme electrophoresis (MLEE)
24
Q

List some Amplification Dependent Methods.

A
  • Random amplified polymorphic DNA
  • Repetitive palindromic extragenic elements PCR
  • Multilocus sequence typing
25
Q

What is a DNA microarray?

A

Grouping at the micron level of DNA molecules attached to a solid support

26
Q

What are DNA chips used for?

A

Investigation of gene expression from an entire organism

27
Q

What is the purpose of nanoarrays?

A

To analyze proteins and gene expression at nanometer spatial resolutions

28
Q

What is Sanger Sequencing?

A

Automated DNA sequencing method

29
Q

What does MALDI-TOF stand for?

A

Matrix-Assisted Laser Desorption–Ionization Time of Flight

30
Q

What is the primary use of MALDI-TOF?

A

Rapid identification of microorganisms

31
Q

What are the three basic nucleic acid molecular diagnostics applications?

A
  • Nucleic acid hybridization assays
  • Nucleic acid amplification techniques
  • Strain typing techniques
32
Q

Nucleic acid hybridization assays – use

A

labeled probes

33
Q

Nucleic acid amplification techniques – use

A

PCR and varients