GM Food Testing Lab

Part 1: Introduction


About 70% of food sold in supermarkets are now genetically modified. This is a touchy subject for many. A lot of people don't like the fact that their food isn't all-natural, but does that really make sense? Genetic modification allows produce to stay fresh longer, makes them invulnerable to certain pests and pesticides, and makes them grow larger and faster. But some people not sold on the idea of eating genetically modified foods. The debate remains heated, but in this lab, we will take a sample of fruit from a supermarket and test to see if it is indeed genetically modified or not.

Part 2: Experiment

(Note that this procedure summary will be slightly abridged, as it is a three-day lab with many steps.)
On the first day, we'll extract the DNA from our apple and corn flour. This will be done with a mortar and pestle; one for each food sample. We will crush the matter as much as we can to break the cell walls, adding 5 mL of water for each gram of food. We have 1.86g of apple and 0.86g of corn flour. Then we'll take 50 microliters of each solution and put them into their respective tubes of InstaGene solution to solidify the DNA. We'll then put the tubes in a waterbath for 5 minutes, then centrifuge them for 5 minutes, then put them in the fridge overnight.
On the second day, we'll get 6 new tubes and label them 1-6, with contents according to the table in the packet. We'll put them all in bigger capless tubes and put them in a foam block and float them in ice water. We'll add 20 microliters of each indicated master mix to each tube, using a new tip for each one, and cap the tubes. Then we'll add 20 microliters of each indicated DNA type to each tube, while using a new tip again. We won't want to mix up the InstaGene pellet at the bottom. Then we'll gently mix the tubes, again without mixing up the InstaGene pellet, and then recap the tubes, and put them in the thermal cycler.
On the third day, we'll do the electrophoresis of the tubes. We'll get our tubes from the cycler and put the PCR tube in the capless tube, and pulse-spin it for 3 seconds. With a fresh tip, we'll add 10 microliters of orange G loading dye to each sample and mix them well. Then we'll add 20 microliters of the molecular weight ruler and 20 microliters of each sample into our gel in the order indicated in the packet. Then we'll run the gel for the time and voltage depending on what gel we're using. Then we'll stain the gels with Fast Blast DNA stain. After that, we'll analyze our results and see what happened.