Profile my DNA, babe.

November 15, 2003 8:10 AM

DNA profiling may be a complex issue, but whatever your take, go ahead and try your hand at genetic sleuthing with this spiffy flash interactive.
posted by moonbird (2 comments total)

It's not terribly interactive, consisting chiefly of "click here, click there, yay, you did it!" Nevertheless it's a good, bite-sized explanation of the DNA profile matching process.
posted by majick at 9:37 AM on November 15, 2003

Eh, pretty good for the layman, but I do research in a molecular genetics lab and thus do this sort of thing every day.

Want a more realistic idea of what gel electrophoresis is like? Well, first you make up a tube consisting of a very small (like 20 microliters or 20*10^-6 or 20 millioneths of a liter) amount of DNA to run and a bit of loading buffer. Basically it's a blue dye that you can see on the gel as it runs and use to detect bands later on. Then we make up the gel itself. It's a lot like making Jell-O really. Add some powder to some liquid, boil, pour into the mold, put a "comb" into it, and let it cool down. The comb is a bit of plastic with some little nubs sticking down and will create wells in the gel. You then place the gel in it's tray into a gel box, add some fluid, and then load the DNA/buffer solution into the wells (you use a micropipeter, not an eyedropper, but it's kinda, sorta the same idea). Plug the box into a power supply and wait about 3 hours or so. Pull the tray out and place the gel in a tray containing some water, add some ethidiome bromide (careful, it's mutagenic!) to this and let it stain for 15 min. or so. Then look at it under a UV lamp and you'll see banding.

If you want a scale you need to also run a marker, a bit of DNA that has already been digested with the size of each band already known. Each gel will look different so you need to use a marker every time as it won't look the same twice. Also interpreting the bands can be a bit tough. Very rarely are they ever as clear and discrete as shown for a variety of reasons.

It's honestly a very simple procedure and something almost anyone could be taught to do in about 20-30 min.
posted by Belgand at 12:03 AM on November 18, 2003