MD Exam 2 Flashcards
Detection system in MD should have three qualities
Sensitivity, specificity, simplicity
Sensitivity
the test must be able to detect very small amounts of target even in the presence of other molecules
Specificity:
the test yields a positive result for the target molecule only
Simplicity:
the test must be able to run efficiently and inexpensively on a routine basis
Regulation Organization and Agents
CLIA
FDA
CMS
CAP
JCAHO
COLA
Clinical validation: Accuracy
a
Clinical validation: Precision
a
Clinical validation: analytic sensitivity
a
Clinical validation: Analytical specificity
a
Clinical validation: Diagnostic specificity
What do we use to lyze cells for NA isolation and analysis?
Detergent SDS, Tween 20
What methods do we use for assessment of quality and quantity?
UV Spectrophotometry (O.D 260-280) and fluorescent dyes
OD260=
1.0 ~50 ug/ml of dsDNA or 4- ug/mL of RNA or ssDNA
After you isolate the DNA you can do direct detection of NA w/
- Restriction endonuclease enzyme digestion
- Gel electrophoresis and ETBr Stain
- Restriction Fragment Length Polymorphism (RFLP)
Restriction Endonucleases (RE) are found only in
microorganisms
RE’s are homodimers that recognize
symmetric dsDNA (palindromes)
Palindromes:
Read the same in both directions
Recognize specific sequences of 4, 5, or 6 nucleotides
Cut by breaking phosphodiester bonds in both strands
Cut DNA into smaller pieces