Genetic Screening and Diagnosis Flashcards
Gel electrophoresis - DNA
LOnger fragments move slower
Fluorescent DNA-binding molecules in gel
Ethidium bromide - intercalating agent that emits light under UV
Southern blotting use to
Find out if DNA sequence present in one or more separated fragments
Southern blotting process
Transfer seaprated DNA to a special paper and then detect fragment of interest using sequence-specific hybridizaiton probe
Steps of southern blotting
Gel electrophoresis…alkaline solutiojn on nitrocellulose gel…nitrocellulose filter…autogradiogram
RFLP analysis used for
Used screen DNA for suspected disease-associated mutations
RFLP analysis summary
Mutation leads to loss or creation of restriction enzynme cleavage site which means different sizes of DNA…altered size detected by southern blot using a probe that hybridizes to the fragment whose size would be different
PCR does what
Amplifies specific DNA segments from small amounts of input DNA
PCR advantages
Don’t need as much blood…increased sensitivity…small regiojn so fewer false positives
Results from analysis of multiple diseassee associated loci ajusted for
SUSPECTED weight of genetic vs. environmental contributions for that disease
Benefits of genetic screening
Tx or lifestyle choices
Kids
Help select partner
probs of genetic screening
Poor predictive value for some conditions…doesn’t test for all disease-causing mutations so could give false sense of secuirty…some discrimination allowed in hiring/health insurance
Most paternity tests done by
Performing PCR with primers spanning VNTRs
Measure blood glucose levels using
Hexokinase and G-6-p dehydrogenase (NADH product detected)
Other wayt to test for glucose
Glucose oxidase and peroxidase using O-dianisidine that turns pink as a result of their reactions
