Getting amount & purity of DNA from 260/280

Paul Cabe cabe at
Mon May 3 16:00:39 EST 1999

Mike Adams wrote:

> I have seen, but do not have a table that provides the quantity and
> purity of DNA in a sample using the readings at 260 and 280. Does anyone
> know of a book that contains this table?
> many thanks
> Mike Adams

  An absorbance of 1 at 260 is equivalent to 50 micrograms/ml of dsDNA.
Absorbance at 280 is useful for checking purity (260/280 ratio should be
less than 1.9, higher suggests RNA contamination).  Many texts reference
this, e.g. the advanced DNA lab manual by Winfrey, Rott and Wortman.

Paul C.

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