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Bacterial Mutation. Get a petri dish, divide and label the bottom (the part with the food):. 0. 5. Your Initials. 10. 15. Now for the Mutation part. Apply one (1) loop of bacteria to the entire “15” pie-shaped wedge Take dish to hood remove lid Irradiate for 5 seconds (only)
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Bacterial Mutation • Get a petri dish, divide and label the bottom (the part with the food): 0 5 Your Initials 10 15
Now for the Mutation part • Apply one (1) loop of bacteria to the entire “15” pie-shaped wedge • Take dish to hood • remove lid • Irradiate for 5 seconds (only) • Replace lid 0 5 Your Initials 10 15
Repeat • Repeat with “10” segment • Irradiate • Repeat with “5” segment • Irradiate • Repeat with “0” segment • DON’T irradiate (why?) 0 5 Your Initials 10 15
DNA Extraction • Chew cheeks- 30 seconds • Rinse cheeks with water from big, blue-capped test tube- 30 seconds • Add 2ml (two droppers up to the line) of “Lysis buffer” • Invert gently 5 times to mix
Function of Lysis Buffer • Detergent • Breaks down membranes and organelles composed of membrane • pH balance
DNA Extraction • Add 5 drops “protease” enzyme • Invert gently 5 times to mix • Place in bath (500 C) for 10 minutes • DNA and associated proteins (“Glue”) before enzyme:
Function of Protease • “Enzyme” • Protease breaks down proteins- other organelles and destructive enzymes • After Lysis Buffer and Protease Enzyme only DNA is intact
Function of Protease • DNA also spreads out after enzyme action
DNA Extraction • Gently layer on ice-cold (ethyl) alcohol • Let stand undisturbed for 5 minutes • Invert slowly 2- 3 times to aggregate DNA
Function of Alcohol • Salt in the water sticks to DNA and induces it to stop repelling other DNA- DNA then re-aggregates • Alcohol induces DNA to come out of solution • DNA is repelled by water and attracted to alcohol, but doesn’t dissolve in it • “Pushed” out of water and very weakly “pulled” into alcohol)
DNA Extraction • So………., where is the DNA and Why? • How pure is the dna?