DNA stains for fluorescence spectroscopy. - (Nov/15/2005 )

Hi
Does anyone know of a DNA stain that operates in high ph conditions and preferably isnt affected by salt concentration. I have tried ethidium bromide but its fluorescence (both with and without DNA) is inhibited by acid.

I am examining the binding of DNA to FeS and wish to dissolve the FeS in acid and then test for the presence of DNA. FeS absorbs UV at the same freq. as DNA so absorbance spectroscopy is useless.

I assume you mean low pH not high pH. How low a pH are you using? Remember that DNA is denatured and degraded at low pH conditions.

Daniel

Molecular biology advice

oops yeah low pH.
the pH will vary as the FeS concentrations vary, but pretty low. The DNA at these pH's is still detectable through UV absorption spectroscopy however I would rather use fluoresence spectroscopy because of its higher accuracy esp in the presence of high salt conc.

Have you any information on the effects og pH on DNA, I havent found much. I have shown myself that when acid is added to DNA its UV absorbance increases and shifts slightly higher peaking at about 280nm.

The change in absorbance you have detected by UV is the DNA denaturing. You might be able to use one of the single stranded DNA stains like picogreen.

Daniel


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