Biotechnology Gel Electrophoresis Regents Biology 2006 2007 Many
Biotechnology Gel Electrophoresis Regents Biology 2006 -2007
Many uses of restriction enzymes… § Now that we can cut DNA with restriction enzymes… we can cut up DNA from different people… or different organisms… and compare it u why? u § § § Regents Biology forensics medical diagnostics paternity evolutionary relationships and more…
Comparing cut up DNA § How do we compare DNA fragments? u separate fragments by size § How do we separate DNA fragments? run it through a gelatin u gel electrophoresis u § How does a gel work? Regents Biology
Gel electrophoresis § A method of separating DNA in a gelatin-like material using an electrical field DNA is negatively charged u when it’s in an electrical field it moves toward the positive side u DNA – Regents Biology “swimming through Jello” +
Gel electrophoresis § DNA moves in an electrical field… u so how does that help you compare DNA fragments? § size of DNA fragment affects how far it travels w small pieces travel farther w large pieces travel slower & lag behind DNA – Regents Biology “swimming through Jello” +
Gel Electrophoresis DNA & restriction enzyme longer fragments wells power source gel Regents Biology + shorter fragments completed gel
fragments of DNA separate out based on size Running a gel cut DNA with restriction enzymes 1 2 Stain DNA u u Regents Biology ethidium bromide binds to DNA fluoresces under UV light 3
DNA fingerprint § Why is each person’s DNA pattern different? u sections of “junk” DNA § doesn’t code for proteins § made up of repeated patterns w CAT, GCC, and others w each person may have different number of repeats § many sites on our 23 chromosomes with different repeat patterns GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGA A GCTTGTAACGGCATCATCATCCGGCCTACG CTT Regents Biology CGAACATTGCCGTAGTAGTAGGCCGGATGC GAA
DNA patterns for DNA fingerprints Allele 1 cut sites repeats cut sites GCTTGTAACGGCCTCATCATCATTCGCCGGCCTACGCTT CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGA A 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 CGAACATTGCCGGAGTAGTAGTAAGCGGCCGGATGCGA A Person 2: more repeats GCTTGTAACGGCCTCATCATCATCCGGCCT ACGCTT CGAACATTGCCGGAGTAGTAGTAGGCCGG ATGCGAA 1 2 DNA fingerprint – 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 fruitfly – DNA 1 + Regents Biology 2 3 4 5 1 2 3 4 5
Uses: Medical diagnostic § Comparing normal allele to disease allele chromosome with normal allele 1 chromosome with disease-causing allele 2 all ele 1 all ele 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 +
DNA fingerprints § Comparing blood samples on defendant’s clothing to determine if it belongs to victim u DNA fingerprinting Regents Biology
RFLP / electrophoresis use in forensics § 1 st case successfully using DNA evidence u 1987 rape case convicting Tommie Lee Andrews “standard” semen sample from rapist blood sample from suspect “standard” How can you compare DNA from blood & from semen? RBC? “standard” semen sample from rapist blood sample from suspect “standard” Regents Biology
Electrophoresis use in forensics § Evidence from murder trial u 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? Mom F 1 – DNA Regents Biology + F 2 child
I’m a-glow! Got any Questions? Regents Biology 2006 -2007
Biodiversity Lab Which plant is most closely related to Botanus curus? Regents Biology 2006 -2007
Botanus curus Sequences DNA CAC RNAGUG AA Regents Biology GTG GAC TGA GGA CTC CAC CUG ACU CCU GAG Val His Leu Thr Pro Glu
Species X Sequences BC CAC GTG GAC TGA GGA CTC DNACAC GTG GAC AGA GGA CAC CTC RNAGUG CAC CUG UCU CCU GUG GAG AA Val His Leu Ser Pro Val Glu BC Val His Leu Thr Pro Glu Regents Biology
Species Y Sequences BC CAC GTG GAC TGA GGA CTC DNACAC GTG GAC AGA GGA CAC CTC RNAGUG CAC CUG UCU CCU GUG GAG AA Val His Leu Ser Pro Val Glu BC Val His Leu Thr Pro Glu Regents Biology
Species Z Sequences BC CAC GTG GAC TGA GGA CTC DNA CAC GTA GAC TGA GGA CTT CTC RNAGUG CAU CUG ACU CCU GAA GAG AA Val His Leu Thr Pro Glu BC Val His Leu Thr Pro Glu Regents Biology
Amino Acid Sequences BC Val His Leu Thr Pro Glu X Val His Leu Ser Pro Val Glu Y Val His Leu Ser Pro Val Glu Z Val His Leu Thr Pro Glu Regents Biology
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