When DNA is treated with diphenylamine under acidic conditions, a blue
compound is formed with the sharp observation maximum at 595 n. This
reaction is produced by 2 deoxypentose in general and is not specific for DNA.
In acid solution the straight from the deoxypentose is converted to the highly
reactive b-hydroxy lerulin aldehyde, which reacts with diphenylamine to produce
a blue complex. In DNA, only the deoxyribose of purine nucleotide reacts so
that the value obtained represents one half of the total deoxyribose produced.
- Commercial sample of DNA – 10 mg.
- Buffer saline 0.15 mL/L NaCl, 0.15 mL/L sodium citrate made up to
- Diphenyl amine reagent: dissolved in 10 gms of pure diphenyl amine in
1 liter of glacial acetic acid and add 25 mL of concentrated H2SO4. This
solution must be prepared fresh.
- Boiling water bath