Genes in a Bottle

Protocol Highlights

What can you teach with the DNA Extraction Kit ? Reinforce the structures of a cell Introduce procedures involved in DNA extraction Preserve student DNA samples

What do you need to do Genes in a Bottle?

Step 1 Label 15ml tube containing water with your initials Gently chew the inside of your cheeks for 30 sec Put the water in your mouth and swish for 30 sec Expel the liquid back into the 15ml tube

Collect cells

Step 2 Add 2 ml of lysis buffer into your tube Cap your tube Gently invert the tube 5 times, DO NOT SHAKE

Why use Lysis Buffer? What is in the Lysis Buffer? 50 mM Tris-HCl, pH 8.0 Maintains pH at which DNA is most stable 1% SDS Breaks open cell and nuclear membrane O S O O O - CH 2 CH 3 SDS

Step 3 Add 5 drops of salt/protease to your tube Cap your tube Gently invert 5 times Incubate at 50ºC for 10 minutes

Why add Salt/Protease? DNA has a negative charge. Salt (NaCl) neutralises the charge because the Na ions sheild the negative charge of the phosphate backbone. To destroy “ DNAses ” (proteins) that break down DNA To break down histones to unwind DNA. To increase the amount of intact DNA obtained

What can we do with the DNA? Genetic testing DNA fingerprinting Genetic engineering

the Inventor was… Sir Alec Jeffreys Genetics Dept Leicester University

Cardiff 3 The scene of the crime Man was charged with murdering Cardiff woman 17 years ago.

Tahini- The Genetic Donor Tabouli and Baba Ganoush The Clones

Step 4 Hold your tube at a 45ºC angle Slowly fill the tube with ICE COLD ethanol (10ml) Leave undisturbed for 5 minutes After 5 minutes, gently invert the tube

Why add alcohol? DNA cannot dissolve in alcohol Cold alcohol makes the DNA clump together and precipitate out of solution Precipitated DNA molecules appear as long pieces of fluffy, stringy, web-like strands

Transferring DNA into glass vials Using a plastic transfer pipette, transfer the DNA strands into the amulet IMPORTANT- put the pipette tip as far as it will go into the amulet or the liquid will not enter Leave about ½ cm from the top of the neck of the tube to put the stopper back into the amulet

DNA Necklace Preparation Push the silicon stopper back into the vial. Apply a small amount of Superglue around the rim of the vial and to the inside of the silver cap. Twist on the silver cap. Hold it down for a few minutes, then allow the cap to dry completely. Once the cap is dry, run the cord through the cap and tie it.

Congratulations! You have just made your very own DNA Necklace !