LECTURE FINAL Flashcards
What is molecular diagnostics?
it is the lab and clinical application of nucleic acid technologies (DNA and RNA) to diagnose and monitor disease states and to evaluate non-disease status.
What is the purpose of molecular pathology?
seeks to explain why a given genetic change should result in a particular clinical phenotype
what is electrophoresis?
movement of molecules by an electric current
what type of charge do DNA molecules have and towards what electric pole do they move?
dna molecules are negatively charged and move towards the positive pole
what is the relationship between dna molecule size and speed at which it travels through gel matrix?
big molecules go slower and don’t migrate as far as small molecules who go faster and migrate further in gel.
what are the 2 most common gels used in molecular?
agarose and polyacrylamide gel
what is agarose?
it is a polymer from seaweed and a component of bacterial culture used for separating larger dna molecules.
what is the relationship between agar concentration and pore sizes?
high concentrations of agar make smaller pore sizes and are used to resolve small dna molecules while low concentrations of agar make large pore sizes to resolve large dna molecules.
what is polyacrylamide gel used for?
to resolve very small dna fragments and single stranded dna.
what type of molecular tests in PAGE used for mostly?
sequencing and mutation analysis.
what is the disadvantage of PAGE?
it is a potent neurotoxin
what is the first step in making an agarose gel?
electrophoresis buffer must be made.
what is the purpose of a buffer?
it carries current and protects samples during electrophoresis.
what are the two most common types of buffer and how are they different?
TAE and TBE. With TAE, dna most faster but with less buffering capacity while TBE has better buffering capacity but dna moves slower.
what is the purpose of adding a loading dye to the dna sample?
- Gives color to the dna for visualization
- Makes dna denser than water so it sinks deep into the bottom of the well.
- has tracking that separates during electrophoresis to indicate progress.
