Molecular Diagnostic Testing Flashcards
What is the purpose of molecular diagnostic testing?
The ability to detect specific nucleic acid sequences in microorganisms or cells before antibody detection.
Define purine bases.
Adenine and guanine.
Define pyrimidine bases.
Cytosine and thymine.
What is the role of RNA in protein production?
Helps convert genetic information within DNA into proteins.
Pyrimidine bases in RNA contains ___ instead of thymine.
uracil.
Nucleosides contain…
Carbohydrate + base.
Nucleotides contain…
Phosphate + carbohydrate + base.
What is the complementary base for adenine in DNA?
Thymine.
What is the complementary base for guanine in DNA?
Cytosine.
What is the complementary base for adenine in RNA?
Uracil.
In what direction is the DNA read during the replication process?
5’ to 3’.
What enzyme is needed for synthesis of DNA?
DNA polymerase.
What is the role of DNA helicase?
Breaks up complementary pairs.
RNA synthesis is catalyzed by what enzyme?
RNA polymerase.
RNA codes for…
Proteins, tRNA, rRNA, long and short noncoding RNA.
Describe a conservative substitution mutation.
Nucleotide base substitution that results in an amino acid with similar properties as compared with the original.
Describe a nonconservative substitution mutation.
Nucleotide base substitution that results in an amino acid with dissimilar properties as compared with the original.
Describe a silent mutation.
Nucleotide base substitution that results in the same amino acid.
Describe a nonsense mutation.
Nucleotide base substitution that results in the creation of a stop codon.
Describe a frameshift mutation.
Insertion or deletion of a nucleotide base that causes a shift in the codon reading frame.
Define polymorphism.
Similar to a mutation or variant, but defined by frequency within a population (i.e., sickle cell anemia).
Describe the strand cleavage method of molecular diagnostics.
Cleaves DNA at specific locations; used to investigate small genomes and detect mutations and polymorphisms.
Define hybridization.
Binding two complementary strands on nucleic acids.
Southern Blot analysis is used to assess what?
Specific DNA sequences.
What is the procedure of a Southern Blot analysis?
Restriction enzymes cleave DNA into small fragments which are separated through gel electrophoresis. The regions are identified through hybridization with labeled probes.
Western Blot analysis is used to assess what?
Proteins that are separated through gel electrophoresis.
The array method of hybridization uses ___ and can be run at the same time.
multiple targets or samples.
What hybridization method would be best for leukemia prognosis, or the diagnosis of an autoimmune condition?
An array method.
Bead arrays uses ___ detection of proteins and nucleic acids. The beads have ___ or single-stranded oligonucleotides attached.
multiplex; antibodies.
The bead array method is good for what types of testing?
Respiratory virus panels.
What does florescence in situ hybridization (FISH) used to detect?
Chromosome abnormalities, T-cell lymphomas, B-cell malignancies, and graft-versus-host disease.
What is the process of florescence in situ hybridization (FISH)?
Cells or thin tissue sections are deposited on a glass slide. Probes are then covalently attached to fluorescent dye to view hybridization.
The most frequent method used in molecular diagnostics is…
Amplification methods.
Define amplification.
Copying nucleic acids to obtain enough for identification (e.g., PCR testing).
Transcription-based amplification methods uses isothermal amplification methods and is different from PCR because…
It doesn’t require thermocycling.
What is the principle behind the ligase chain reaction?
Amplifies probes rather than target DNA. Two primers are attached to the target DNA sequence and then the primers are joined and amplified.
Define ligase.
An enzyme that joins two DNA chains by creating phosphodiester bonds.
Describe the Sanger (chain termination) DNA sequencing method.
DNA replication that uses fluorescent-label ddNTPs.
Describe the pyrosequencing DNA sequencing method.
Generation of light when nucleotides are added to a growing strand of DNA.
