A Molecular McGuyver
I was fighting the insomnia demons last night and letting my mind wander around about things. I started thinking about class and how I can make this unit on DNA more fun for the students. I started thinking the stuff I have done, and I thought it would be cool if we could actually extract some DNA from some plants or other cells. I then lamented over the fact that alas I do not have the materials to do this.......then my brain began to race around my stored files and pieced together a little theory. I think I can extract DNA from some plants using some household items. I am going to test it out on Friday (too busy until then) and then if it works deliver it to my class as an activity.
Here is my thought:
Blend up some peas, spinach, etc. Get them good and liquified then strain them through a straining device to get the cells as separated as possible. Once I do this I will add some dishwashing detergent. Why? Well we need to open the cells up to get the DNA out right? Well cell membranes are made of Phospholipids.....you know....fat. Well what do we use dish detergent for....yup, break apart grease....the same structure as fat. Ok, now that we have the cell membrane and the nuclear membrane open the DNA is released, but how do we get the DNA to clump together and separate itself from all the other debris in there? Well the DNA is wrapped tightly around proteins, it won't let go as long as those proteins are intact. So how do we break apart those proteins? We use enzymes, what household items contain enzymes built to break up protein? Meat tenderizer and contact solution! So now we add one of those to the mix and break apart the proteins. The DNA is now by itself, but it is still floating around inside our pea/detergent/contact solution mix. How do we get it away from all that stuff? Well we have to somehow attract the DNA away from the mix. If I slowly pour a layer of rubbing alcohol on top of all this I will give a nice comfortable area for DNA to hang out in. It like the solution of alcohol, it is drawn to it. So the DNA should rise to the alcohol layer and clump together. With a coarse utensil (toothpick) I can gently remove the DNA from the alcohol and Ta DA! This should work, I will let you know.
Anyway that is the sort of stuff buzzing around my melon when I can't sleep. That and old Foxtrot comics. I love those books. I wonder if there are any new ones out?
Alright I have had enough thinking for tonight, I will keep this short and sweet.