I've tried the Qiaex II Gel Extraction Kit (Qiagen) with good results.
Thanks for the response I've received.
To Vince Mulholland: My gels are stained with ethidium bromide. I tried to
concentrate the DNA extracted by freeze/thawing and run it on an agarose gel
without prior reamplification, just to see if I got any DNA out of my
extraction. I didn't so I concluded that the problem was the extraction
rather than the following PCR amplification.
Vince Mulholland wrote:
>> Rather than your extraction method, it could be to do with the staining
> method you use. Do you silver stain your DGGE gels? If you silver stain,
> do you use a stop solution which contains acetic acid? The acetic acid,
> after silver staining, seems to render DNA refractory to amplification
> (presumably due to nick of the strands).
>> Vincent Mulholland,
> Senior Plant Pathologist,
> Diagnostics & Molecular Biology Section,
> Scottish Agricultural Science Agency,
> East Craigs,
> Edinburgh EH12 8NJ, U.K.
>> URL: http://www.sasa.gov.uk/> E-Mail: Vince.Mulholland at sasa.gov.uk> Tel:+44(131)2448845 Fax:+44(131)2448912
> How do you extract DNA from a polyacrylamide gel?
>> I run DGGE gels and need to excise the bands for PCR reamplification and
> sequencing. I've tried cut out bands and freeze/thaw them ×3 in water
> but didn't get any product after the following PCR. Please, let me know
> if you know of a good method to recover the DNA.
>> Thank you
> Lise Larsen