Fun with DNA! (SFW mehtod)

February 11, 2005 8:43 PM

How to extract DNA from any living thing. Don't just watch the show, create a CSI lab in your own kitchen!
posted by numlok (12 comments total)

Didja hear the one about
posted by rxrfrx at 8:45 PM on February 11, 2005

Wouldn't ya just know it... First FPP, and I wear my noob colors proudly.
I did do a search, but only for "extract DNA".
My bad (DAMMIT!).
Truly sorry to waste time and (precious blue) space.
delete.
posted by numlok at 8:52 PM on February 11, 2005

I missed the previous FPP, numlok, so thanks.
posted by weapons-grade pandemonium at 8:57 PM on February 11, 2005

For some reason, the title of the page made me think of of the "King and Queen of Cheese" episode of Cow and Chicken.

Pity the process needs a larger quantity of biological matter than could be comfortably extracted from my body. I was so looking forward to seeing what I could get from some spit and an in-cheek-scraping.

(No, I will not put cups of semen in the blender.)
posted by brownpau at 9:46 PM on February 11, 2005

Please, unless all your friends are biologists, do not try this at a party.
posted by greatgefilte at 10:21 PM on February 11, 2005

Oh, greatgefilte, I meant to mention this in the old DNA thread before it got locked: I tried the hi voltage/SB buffer system for DNA gels, and it kinda sucks. You can run at 300V without melting your gel, but it will only clearly resolve stuff in the roughly 200-1500 bp range, and it's still kinda streaky. I couldn't get it to look like the pictures on the website of whomever's selling the stuff.
posted by rxrfrx at 12:58 AM on February 12, 2005

I missed this the first time round too, and it's cool! Up there with measuring the speed of light with some marshmallows and a microwave oven.
posted by carter at 7:13 AM on February 12, 2005

rxrfrx, it takes a little tinkering to get it to work nicely for each particular application. Did you make it yourself or buy it from the company? Maybe your loading dye has too much salt? What percentage of agarose are you using?

Drop me an email, I'll try to make it work for you!
posted by greatgefilte at 11:35 AM on February 12, 2005

Why did I just add detergent to my pea soup?

Ain't that the eternal question.
posted by Wolfdog at 12:21 PM on February 12, 2005

Why did I just add detergent to my pea soup?

Why this works:

The blender breaks walls around plant cells.

Detergents and salt break down exposed cell membranes into component fatty acids: endoplasmic reticulum, nuclear and cell membranes, Golgi bodies.

This gets the DNA out of the cell nucleus.

I'm pretty sure the meat tenderizers (enzymes) break down proteins like nucleases (DNase, RNase) that get released by the detergent/salt treatment.

These proteins would otherwise break down the DNA and ruin the extraction. Destroying (denaturing) the nucleases helps keep the DNA intact.

Ethyl alcohol pulls the DNA out of the detritus of cell materials.
posted by AlexReynolds at 12:40 PM on February 12, 2005

I've tried the SB buffer too...my results were similar, rxrfrx. Works fine unless you want to resolve anything less than about a kb or so.
posted by statolith at 5:13 PM on February 12, 2005

Another cool DNA related link (I doubt it warrants a new FPP): dnahack.com.
posted by numlok at 11:13 PM on February 16, 2005