Dye content (spectrophotometrically): ≥ 80 %
Identity (UV/VIS-Spectrum): passes test
Absorption maximum λmax. (ethanol 50 %): 628 - 632 nm
Spec. Absorptivity A 1%/1cm (λmax; 0.003 g/l; ethanol 50 %): 1860 - 2370
TLC-Test: passes test
Loss on drying (110 °C): ≤ 5 %
Suitability for microbiology: passes test