Seliwanoff’s Test- Definition, Principle, Procedure, Result, Uses

Seliwanoff’s test definition

The Seliwanoff’s test is employed to differentiate between carbohydrates containing an aldehyde group and those containing a ketone group (ketose) (aldoses). This test employs a timed colour reaction peculiar to ketohexoses.

Objectives of Seliwanoff’s test

  • to evaluate whether or not a sample contains ketohexoses.
  • to separate aldoses from ketoses.

Principle of Seliwanoff’s Test

  • Concentrated HCl and resorcinol constitute the test’s reagents.
  • By hydrolyzing polysaccharides and oligosaccharides with acid, simpler sugars are produced.
  • Aldoses dehydrate more slowly than ketoses do.
  • Ketoses dehydrate in the presence of concentrated acid to create 5-hydroxymethyl furfural.
  • During a series of condensation reactions, dehydrated ketose reacts with two equivalents of resorcinol to form xanthenoid, a complex (not a precipitate) exhibiting a deep cherry red colour.
  • When the test is prolonged, aldoses may have a faint pink to cherry red hue upon reaction.
  • The product and response time of the oxidation process make it simpler to differentiate various carbohydrates.
  • Due to the fact that sucrose and inulin are digested by acid to produce fructose, these other carbs also produce a favourable outcome for this test.



  • Add 0.05 percent resorcinol (m-hydroxybenzene) to 3 N HCl to get Seliwanoff’s reagent.
  • Combine 100 ml of water with 33 ml of concentrated HCl after dissolving 50 mg of resorcinol in it.
  • Test sample
  • Distilled water

Materials required

  • Test tubes
  • Test tube stand
  • Pipettes


  • Water bath

Procedure of Seliwanoff’s Test

  • Fill one test tube with the test sample and another with distilled water to operate as the blank.
  • 2 ml of Seliwanoff’s reagent should be added to each test tube.
  • Keep both test tubes submerged in water for one minute.
  • Take notice of the colour formation as you watch it happen.

Result and Interpretation of Seliwanoff’s Test

  • The formation of the cherry-red complex is an indication of effectiveness, demonstrating that the submitted sample contains ketoses.
  • A negative outcome, or one where the colour does not emerge at all or rather follows a considerable amount of time, indicates that the material under examination does not contain ketoses.

Uses of Seliwanoff’s test

  • Seliwanoff’s colour reaction is utilised in the colorimetric measurement of fructose in fermentation medium.
  • The concentration of ketoses in a particular sample can be determined using a modified version of this technique.

Limitations of Seliwanoff’s test

  • High levels of glucose or other sugars may cause Seliwanoff’s reagent to produce similar-colored molecules, which might cause interference.
  • Through the catalytic action of acid, prolonged boiling can convert glucose to fructose, causing the production of cherry red complex and hence a false-positive test outcome.
  • A different test is needed to identify the specific ketose sugar because this test is generic and cannot discriminate between different types of ketoses.

References and Sources

  • Tiwari A. (2015). Practical Biochemistry. LAP Lambert Academic Publishing.
  • Sánchez-Viesca, Francisco & Gómez, Reina. (2018). Reactivities Involved in the Seliwanoff Reaction. 10.11648/j.mc.20180601.11.
  • 4% – https://en.wikipedia.org/wiki/Seliwanoff%27s_test
  • 3% – https://www.researchgate.net/publication/313745155_Practical_Biochemistry_A_Student_Companion
  • 2% – https://www.youtube.com/watch?v=vOWoWxEdy0I
  • 2% – https://diabetestalk.net/blood-sugar/chemical-test-to-distinguish-between-glucose-and-fructose
  • 2% – https://biokamikazi.files.wordpress.com/2013/10/merged_document.pdf
  • 1% – https://www.oxfordreference.com/view/10.1093/oi/authority.20110803100453548
  • 1% – https://generalchemistrylab.blogspot.com/2011/12/seliwanoffs-test.html
  • 1% – http://en.edubio.info/2017/02/seliwanoffs-test-for-ketose-sugars.html
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