DNA probing and DNA hybridation

Question 1

what is a DNA probe?

Answer 1

short, labelled, single stranded DNA sequence that can identify a specific allele
- it does this by binding to a complementary DNA sequence

Question 2

what can DNA probes determine?

Answer 2

whether an individual carries a mutated allele responsible for a genetic disorder

Question 3

what is the process of screening DNA for a specific allele using DNA probe?

Answer 3

• denaturation = DNA strands are heated causing them to separate into 2 single stranded
• fragmentation = digest the DNA sample into fragments using restriction enzymes
  -mixing = add fluorescent or radioactively labelled DNA probes
• hybridation = DNA probes bind with target sequence
• identification = visualise any DNA probes which has hybridised to DNA fragments under UV light (florescent) and x ray (radioactive)

Question 4

what are DNA microarrays?

Answer 4

allows for simultaneous screening of many genes using multiple DNA probes through high throughput screening

Question 5

how does DNA microarrays work?

Answer 5

• extract DNA from species or cells of interest
• fragment and flourescently label these DNA samples
• mix labelled DNA and wash it over microarray probes
  -DNA fragments which match any of the probes will hybridise
• array is then viewed under UV light
  -any fluorescent spots that sample contains theses fragments

Question 6

what are applications of DNA probes in genetic screening?

Answer 6

• identify individual carrying specific soles that may lead to genetic disorders
• determine how patient will respond to certain drugs, useful in targeted cancer therapies
• evaluate susceptibility to diseases due to inherited or mutated alleles, aiding in preventive healthcare decisions