PAGE purification and analysis

[Dr Engelbert Buxbaum]

Am 06.04.2008, 20:15 Uhr, schrieb yan sun <yansun2005 from gmail.com>:

> Dear all,
> I was confused  by my PAGE gel purification for a while.
> I tried to purified spin labeled DNA and non labeled DNA through 20%
> polyacrylamide gel. My DNA is around 8,200 dalton, the attached spin  
> label
> material MW is around 200g/mole, which means I try to separate two DNA
> bands, the molecular weight difference is 200 dalton.

I do PAGE for proteins rather than DNA, but perhaps some hints:
- The MW difference is very small, only about 3%. Try optimizing the  
separation by using gradient gels and by using a gel concentration where  
your molecule ends up 2/3 - 3/4 down the gel.
- If you can find conditions where labeled and unlabeled DNA have  
different net charge that would greatly improve separation. Without  
knowing exactly what label you attach where, it is difficult to give  
specifc advice.