DNA Fingerprinting
DNA Fingerprinting
-Ex: Crime Scene analysis (matching DNA samples)
How it works:
- -DNA is a string of nucleotides attached together with a sugar-phosphate backbone (sequence of bases vary)
- -Restriction enzyme: enzyme that breaks DNA sting at particular sequences of bases
- - results in fragments of DNA of various lengths
- -Because everyone has slightly different DNA sequences, if you have DNA samples from >1 person and incubate those samples with the same restriction enzyme, you'll get different number and sizes of fragments
- -After treating DNA samples with restriction enzymes, you can zap it them with electricity through an agarose gel, and this will seperate the DNA fragments by size
- -Then stain the gel…to see where DNA bands are
- DNA has a negative electrical charge (btw, histones are positively charged -> why chromatin possible)
- Add 5microL of loading buffer (blue "LB") to each sample tube.
- Loaded molecular ladder (DNA cut into known size fragments) and samples into wells.
- Run gel electrophoresis ~30 minutes at 200Volts on a 1% agarose gel
- Soak in Ethidium Bromide (.01%) solution in Tris-Acetate-EDTA buffer
Here is a short video that is straight and to the point about this lab. I wish it didn't cut off but I will keep looking for more videos to post!
That's an awesome video!
Thanks
They didn't change pippets, so it's not very valid, :) but it is a good example.
Change your pipette tips or be struck down by the might of GOOOOOOOOD!
Wow, good example?
page revision: 11, last edited: 03 Mar 2010 02:30