Molecular Diagnostics Supplement (4)

Question 1

How does hybridization work

Answer 1

A single stranded DNA binds to either another stand of DNA or RNA with the complementary strand to form a DNA-DNA Hybrid or a DNA-RNA Hybrid

Two types

Question 2

Southern blotting

Answer 2

Hybridization where both probe and nucleic acid are DNA

Question 3

Northern Blotting

Answer 3

Hybridization where prob is DNA and target is mRNA

Question 4

Describe PCR

Answer 4

Double stranded DNA is obtained and denatured using heat

Solution is cooled to allow primers to anneal to each end of DNA

Taq Polymerase used to synthesize copies of DNA by extending the primers on both ends. This doubles in each cycle.

Question 5

Describe an ELISA

Answer 5

An immunological technique which tests for the levels of a specific antigen or antibody in a biological sample

The antigen or antibody is conjugated to a reactive enzyme which changes color

Question 6

What is an indirect elisa

Answer 6

Measures the amount of an antibody in a sample

Produces a secondary antibody conjugate

Question 7

What is a sandwhich elisa

Answer 7

Measures the amount of an antigen in a sample

Question 8

What type of ELISA is used for HIV detection

Answer 8

An indirect ELISA, measures the amount of antibodies the body produces

Question 9

What type of ELISA is used for

Answer 9

Uses a sandwhich ELISA to test for Troponin antigens

Question 10

How does a UPT work

Answer 10

This is an example of a sandwich ELISA

Reaction site (where you pee) has free hCG antibodies which bind to hCG in urine

Test site receives bound antibodies and binds to other in Test site, turns a color if positive