DNA probes etc

what is a DNA probe x3

short sequence of dna
label attached that can be detected
located specific allele

general process using DNA probes

probe has comp base sequence to target allele
detectable label attached eg fluorescence
DNA treated to exposed bases
probe will hybridise to target allele and detected

process of gel electrophoresis (6 stages)

1. RE used to hydrolyse DNA into fragments
   2. treat DNA to exposed bases
   3. separated by gel electrophoresis
   4. separated DNA fragments transferred onto nylon membrane and incubated with DNA probes with label
   5. if the allele is present the DNA probe will hybridise with it
   6. fluorescent= viewed with UV; radioactive= x-ray film

dna microarray process 7 stages

1. dna probes attached to microscopic spots on a glass slide

2. labelled

3. treat and expose DNA

4. sample washed over dna

5. if present, will hybridise with probe

6. array washed and viewed under uv

7. spots identified contain allele of interest

uses of probes

heritable conditions

drug response

health risks

use of results

genetic counselling

personalised medicine- predict response so only most effective prescribed