Threadless recently hosted* a t-shirt contest for Jeffery Smith‘s Institute for Responsible Technology: the No GMO t-shirt design challenge (see Karl’s post Vote for talking, not fighting for more details). One of the shirts really struck me: GMO Shortens Life Span by Michael. The artist proposes an equation:
plants + DNA = death
This slogan really makes me wonder – does the artist know that plants have DNA? Does he know that his own cells are teeming with DNA? That without DNA, life wouldn’t exist? Do most people know that DNA is essential for life? What would the average person say if told that they eat about 100 thousand miles of DNA in the average meal?
If this is the level of understanding, or rather, misunderstanding, that persons have, can we ever expect to have useful discourse on the subject of biotechnology or even biology itself? This worries me greatly. Just in case anyone out there reading this is concerned that DNA is dangerous, I’d like to provide a simple recipe that anyone can use to see and touch DNA for themselves.
As shown in the picture below, DNA is tightly packed in each cell. It’s wrapped around proteins called histones, then coiled into the familiar X chromosome shape. The amount of DNA per cell depends on the species, but each cell has about 9 feet of DNA in it. Since each meal contains tens of millions of cells, you eat about 7 to 10 miles of DNA at each meal!
There are a lot of DNA extraction recipes out there, but there are a few essential steps. The DNA must be freed from the cell membrane and the membrane of the nucleus. Then, the DNA needs to be separated from the membrane bits, proteins, and other cellular parts. Finally, the DNA needs to be precipitated, or brought out of solution by becoming a solid instead of being dissolved in the solution.
- Source of DNA. Fruit, especially banana or strawberries, works great because they have a lot of DNA per cell. Onions have a lot of DNA per cell too, but make for a much less pleasant smelling DNA extraction than berries or bananas.
- Detergent, such as shampoo or dish soap. Clear detergent is better so dye doesn’t cover up the action.
- Coffee filter to remove proteins, cell membrane parts, and other cellular gunk from your DNA solution.
- Table salt to precipitate proteins and carbohydrates.
- Ethanol to precipitate the DNA. Rubbing alcohol is ethanol, preferably 95%.
- A plastic sandwich baggie.
- 3 cups.
- A plastic teaspoon.
- A test tube or narrow glass like a shot glass.
- Pour some rubbing alcohol into one of the cups and put it into the freezer.
- Prepare the fruit.
- If using a banana, peel the banana. Set aside of eat half of it and put the other half into a plastic baggie.
- If using strawberries, cut up about 5 medium strawberries into fourths. Put the pieces into a plastic baggie.
Safety note: if you are tempted to taste the DNA, just remember that there is shampoo and rubbing alcohol in there and that these things are generally not good to eat! DNA itself, though, is perfectly safe – we eat it in every meal. Really want to eat DNA? Check out these instructions for building an edible model.
*Just in case you were wondering, the contests aren’t vetted by Threadless, they are run by a separate site, Atrium. This was important for me, because I rather like Threadless, but I prefer to avoid patronizing companies whose publicized ethical stance I disagree with.