1. Unit 2-5 Notes Mr. Hefti – Pulaski Biology Genetic Testing

2. 1. Summary of Steps Gene testing –Collect cells (blood sample) –Make copies of the DNA (PCR) –Separate the DNA (gel electrophoresis)

3. 2. Gel Electrophoresis DNA moves through gel based on size –Smaller fragments travel faster than larger fragments!!!

4. 3. Huntington Disease Gene CAGHD gene contains extra CAG nucleotide repeats, therefore are larger in size than normal gene

5. 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

6. 5. Example HD Pedigree