Aim Biotechnology Gel Electrophoresis Warmup HW Regents Biology
Aim: Biotechnology Gel Electrophoresis Warm-up: HW: Regents Biology
Many uses of restriction enzymes… ◆ Cut up DNA from different people… or different organisms… and compare it why? ▪ ▪ ▪ forensics medical diagnostics paternity evolutionary relationships and more… Regents Biology
Comparing cut up DNA ▪ How do we compare DNA fragments? ◆ separate fragments by size ▪ How do we separate DNA fragments? ◆ gel electrophoresis Regents Biology
Gel electrophoresis DNA is moved by size and charge ◆ DNA is negatively charged ◆ DNA is in an electrical field it moves toward the positive side Regents Biology
Gel electrophoresis ▪ Size of DNA fragment affects how far it travels �small pieces travel farther �large pieces travel slower & lag behind DNA – Regents Biology →→→→→→→ “swimming through Jello” +
Gel Electrophoresis DNA & restriction enzyme longer fragments wells power source gel shorter fragments Regents Biology + completed gel
DNA fingerprint ▪ Why is each person’s DNA pattern different? ◆ sections of “junk” DNA ▪ doesn’t code for proteins ▪ made up of repeated patterns �each person may have different number of repeats GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA GCTTGTAACGGCATCATCATCCGGCCTACGCTT CGAACATTGCCGTAGTAGTAGGCCGGATGCGAA Regents Biology
DNA patterns for DNA fingerprints Allele 1 repeats cut sites GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA Cut the DNA GCTTGTAACG GCCTCATCATCATCGCCG GCCTACGCTT CGAACATTGCCG GAGTAGTAGTAGCGGCCG GATGCGAA 1 2 – DNA → allele 1 Regents Biology 3 +
Differences between people Person 1 cut sites GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGAA Person 2: more repeats GCTTGTAACGGCCTCATCATCATCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAGGCCGGATGCGAA 1 DNA fingerprint 2 – DNA → person 1 person 2 Regents Biology 3 +
Uses: Evolutionary relationships ▪ Comparing DNA samples from different organisms to measure evolutionary relationships turtle snake rat squirrel – DNA ↓ + Regents Biology 1 2 3 4 5 1 2 3 4 fruitfly 5
Uses: Medical diagnostic ▪ Comparing normal allele to disease allele chromosome with normal allele 1 chromosome with disease-causing allele 2 alle le 1 alle le 2 – DNA ↓ Example: test for Huntington’s disease + Regents Biology
Uses: Forensics ▪ Comparing DNA sample from crime scene with suspects & victim suspects S 1 S 2 S 3 crime scene V sample –DNA ↓ Regents Biology +
Electrophoresis use in forensics ▪ Evidence from murder trial ◆ Do you think suspect is guilty? blood sample 1 from crime scene blood sample 2 from crime scene blood sample 3 from crime scene “standard” blood sample from suspect OJ Simpson blood sample from victim 1 N Brown blood sample from victim 2 R Goldman Regents Biology “standard”
Uses: Paternity ▪ Who’s the father? – DNA ↓ Regents Biology + Mom F 1 F 2 child
- Slides: 14