Unit 2-5 Notes

Mr. Hefti – Pulaski Biology

Genetic Genetic

TestingTesting

1. Summary of Steps

• Gene testing

–Collect cells (blood sample)

–Make copies of the DNA (PCR)

–Separate the DNA (gel electrophoresis)

2. Gel Electrophoresis

• DNA moves through gel based on size– Smaller fragments Smaller fragments

travel faster than travel faster than

larger fragments!!!larger fragments!!!

3. Huntington Disease Gene

• HD gene contains extra CAGCAG nucleotide repeats, therefore are larger in size than normal gene

4. Results• Compare patients’ DNA test results to

control samples

Larger DNA fragments end

up here

Smaller DNA fragments end

up here

Lane 1 = no sample

Lane 2 = Positive control

Lane 3 = Negative control

Lane 4 = Patient A

Lane 5 = Patient B

Lane 6 = Patient C

5. Example HD Pedigree