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Recombinant dna technology

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  • 1. Recombinant DNA Technology ORHow to Mess with DNAfor Fun and Profit

2. ORHow to Make a Mouse Glow in the Dark 3. What the heck is RecombinantDNA?Recombinant DNA is what you get whenyou combine DNA from two differentsources.For example: Mouse + Human DNAHuman + Bacterial DNA Viral + Bacterial DNAHuman + (other) Human DNA(Its sort of like Frankenstein-DNA!) 4. Why Make Recombinant DNA? Recombinant DNA Technology May Allow Us To: Cure or treat disease Genetically modify our foods to increaseflavor, yield, nutritional value or shelf-life Better understand human genetics Clone cells or organs 5. Molecular Biologys Best Friends: Bacteria Why use bacteria? Theyre relatively simple organisms. They reproduce very quickly and asexually (thismeans that the daughter cells will contain theexact same DNA as the parent cell). Its pretty easy to get DNA back into the bacteriaafter youve changed it. We can mess around with their DNA and kill alot of them during our experiments and nobodygets mad. ;-) 6. Now for a littlevocabulary 7. PlasmidsSmall, circular pieces of extraDNA found in bacteria. Plasmids often carry antibiotic resistance. 8. Restriction Enzymes: Molecular ScissorsA restriction enzyme (RE) is a specialized protein thatcuts DNA in a very specific place. Different REs cut at different places along thenucleotide sequence. 9. Restriction Enzymes, continued 10. Restriction Enzymes, Cont. Any piece ofDNA cut witha certainrestrictionenzyme willstick to anyother piececut with thatsame RE,even if theycome fromdifferentsources. 11. What do you noticeabout these restrictionsites (placeswhererestrictionenzymescut)? 12. Cool, but what good are they?Lets find out 13. Insulin for Diabetics: The Old Way 14. Insulin for Diabetics: The New Way 15. Step 1: Isolate (find) the human generesponsible for producing insulin and decide where you want to put it.In this case, we decide to put our humanDNA into the plasmid of E. coli, a verycommon bacterium. 16. Step 2: Get the bacterial (plasmid) DNAout of the E. coli. We do this by basically exploding them. Step 3:Cut your human DNA and bacterial DNAwith the same restriction enzyme. 17. Step 4:Mix the cut human DNA, which contains the insulin gene, with the cut bacterial DNA.Theyll stick together because they were cut with the same restriction enzyme. 18. Step 5:Get your new recombinantplasmid back into the bacteria. This is easy because bacteria will take in DNA thats floatingaround near them. We call this transformation. 19. Step 6 Find the bacteria that have taken up yourrecombinant plasmid amongst the riff-raff inthe petri dish. Remember how I said that many plasmids contain a gene that makes them resistant to antibiotics? How might you use that to find your special bacteria? 20. Voila!!Now your E. coli will use its new DNAto make human insulin!Because they reproduce so quickly, youll soon have thousands, millions, or billions of human insulin making machines.By filtering out the bacteria after theyve madeinsulin, youve got clean human insulin that canbe packaged and given to diabetic patients. YAY! 21. Gene therapy: another way to use recombinant DNA 22. How do you think you could makea mouse glow in the dark?Hint: Fireflies have a gene calledluciferase that makes their little bums light up 23. You can do itinplants too! 24. What genes do you think wereintroduced to this poor mouses DNA?