Calculate to Nuecleic Acid on BeckMan DU-64

[Monthop Champaruang]

Dear sir,
  How do we calculate the nuecleic acid (as the same we read on DU-64,
program 10, with the background correcting at A320)  from A260, A280 and
A320 value.
  I tried to use the Warburg equation, NuecleicAcid = 62.9xA260-36.0xA280
by direct taking the A260 and A280 but It is a big difference from
Nuecleic acid readed from DU-64. And already tried to use the equation,
[62.9x(A260-A320)]-[36.0x(A280-A320)], but some still have big difference.
  Would you mind telling me How the DU-64 calculate the NuecleicAcid or
How we calculate the Nuecleic Acid.
  Thank you very much for any comments.

Regards,
Monthop Champaruang.
P.S. sorry about my english.


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