Toluidine blue solution is used in testing for lignin, a complex organic molecule that bonds to cellulose fibres and strengthens and hardens the cell walls in plants. A positive toluidine blue test causes the solution to turn from blue to pink. A similar test can be performed with phloroglucinol-HCl solution, which turns red.

Dye Content: >80%

Molecular Formula: C15H16ClN3S

Molecular Weight: 305.83 g/mol

Melting Point: 156-158 °C(lit.)

Absorptivity (1%/1cm): >1200 Loss on drying: <8.0%

Solubility (0.1% dist. Water): Clear blue solution

Hazard Phrases: Not considered harmful under normal laboratory conditions

Cas No: 92-31-9
Einecs No: 202-146-2