Diacetyl Monoxime (DAM) Test
Definition
A FSSAI-approved colorimetric rapid test for urea: urea reacts with DAM under acidic conditions to produce a yellow-to-orange chromophore readable at 540 nm. Detects urea above the natural bovine milk range of 200-400 mg per litre.
- Detects
- Urea adulteration in milk
- Chromophore colour
- Yellow to orange
- Reaction condition
- Acidic medium
- Read wavelength
- 540 nm
- Regulatory status
- FSSAI-approved rapid colorimetric test
Common questions
Why does the DAM test need a natural urea baseline?+
Milk naturally contains urea from normal protein metabolism, typically in the range of 200 to 400 milligrams per litre, so a positive DAM reaction only indicates adulteration when the measured level clearly exceeds this physiological range rather than any detectable urea at all.
What can cause a false interpretation with the DAM test?+
Because the test is colorimetric, factors like milk turbidity, fat content, or improper timing of the colour reaction can shift the absorbance reading, so labs typically confirm a borderline or high result with a second quantitative method rather than relying on a single colorimetric pass.
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