Science Class- Dec. 8-12

This week, Mr. Finley told us that his moon rock was stolen, and he found a hair where it was.  He has decided to compare the DNA in the hair with DNA of some suspects.  I really doubt that it was actually stolen, because what are the chances of having to do a DNA test the week we are learning about DNA?  Also, it was only the 7th grade science classes that were tested, and not the study hall, homeroom, or 8th grade classes that were tested.  In order to find the DNA of the suspects, we had to do the following lab.  

First, we had to swab the mouthes of the suspects so that we had their cheek cells on the swap.  We put the cheek cells in the test tube.  Then we added the lysis. Lysis is made from 1/5 tsp salt, 1 tbsp baking soda, 1/2 to 3/4 cup of water, and a small squirt of dish soap (gets rid of grease).  he lysis breaks down the cell membrane and organelles, which are made from lipids, and leaves behind the proteins and DNA.  After that, we added some pineapple juice to break down the proteins.  Finally, we slowly added 2 ml of alcohol (I think it was really strong or something).  We started to see some nasty-looking white stuff at the bottom.  

On Thursday and Friday, we learned about electrophoresis by doing a simulation at www.learngenetics.utah.edu/content/labs/gel/.  Electrophoresis is a way to sort and measure DNA strand by running an electrical current through it.  First, you make the gel.  Then, you set up the gel apparatus.  Next, the DNA samples are loaded into the gel.  After that, the electrical current is hooked up and run through the gel.  Finally, the gel is stained and the results are analyzed.  DNA could be used to solve crimes if there is any DNA on the crime scene.  One of the problems with using DNA is that there may be a mistake, and an innocent person may get in trouble.