Genomic DNA purification - Very low 260/280 or <0.01ug/ml!!! (Dec/29/2004 )

Warm Christmas Wishes and Happy 2005 to ALL!!

This time, I have a set of Genomic DNA samples purified by QIAmp DNA Blood Mini Kit according to manufacturer's instructions. In some samples the 260/280 ratios are very low (some 1.26- some 0.88), in all the concentration os <0.01 ug/ul...

The company's troubleshooting is not very useful due to the fact that Protease is stored in aliquots, 100% alcohol was used, > 1 million cells were used for extraction, etc, etc, and more importantly, the sources of these samples are no longer available!! so this is ALL or NONE...

I was thinking in re-extract DNA by using this kit or speed-vac concentration...

What do you think/suggest?

I will REALLY appreciate you responses!!

Thanks

Spectro analysis for genomic DNA is not always thrust worthy.

What is the purpose of the DNA you isolated?

I had a similar problem. So precipitated the samples by using standard protokoll (NaAc and EtOH). But what are you using th samples for?
The second time I did no OD measuring, and the real time pcr made no problems though. So it depends on the application.
Good luck!

thanks for your replies...

DNA will be used for PCR amlification.