Verification of reducing sugar with tetrazolium red
sodium hydroxide solution 7,5% C R 35 S (1/2)-26-37/39-45
2,3,5-Triphenyl tetrazolium chloride
burner (preferably alcohol)
- Add a very small spatula-tipful triphenyl tetrazolium chlorid to the test tube and dissolve this with approx. 1 ml water.
- One now adds a small spatula tipful glucose along with 0.5 ml diluted sodium hydroxide and gently warms with the burner.
- Soon a reddish color appears which then quickly becomes deeper and cloudy.
- The diluted residues can be discharged into the drainage.
Triphenyl tetrazolium chloride is reduced to a red-colored open chain compound by α-Hydroxyaldehyde, e.g. reducing sugar. Hereby it acts more specifically than Fehling's solution.
Coloration due to glucose and triphenyl tetrazolium chloride.
Derived from experiement 61.2, "Red Tetrazolium",