Crystal violet (C.I. 42555) is a CERTISTAIN® dry dye that can be used to produce a Crystal violet staining solution to differentiate Gram-positive and Gram-negative bacteria in samples of human origin. In the case of Gram-positive bacteria, the bacteria retain their dark blue / dark purple color even after the treatment with decolorizing solution. On the other side Gram-negative bacteria are stained red or pink with the counterstain. The CERTISTAIN® dry dye can be used for clinical diagnostic purposes as it is certified and registered as IVD and CE product.
EC index number
3204 13 00
Structure formula Image
Crystal violet (C.I. 42555) for microscopy Certistain®. CAS 548-62-9, pH 2.5 - 3.5 (10 g/l, H₂O, 20 °C). MSDS and product info below.
1.19 g/cm3 (20 °C)
189 - 194 °C
2.5 - 3.5 (10 g/l, H₂O, 20 °C)
220 - 400 kg/m3
LD 50 oral
LD50 Rat 420 mg/kg
Safety Information according to GHS
H302: Harmful if swallowed. H318: Causes serious eye damage. H351: Suspected of causing cancer. H410: Very toxic to aquatic life with long lasting effects.
P273: Avoid release to the environment. P280: Wear eye protection. P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
10 - 13 Other liquids and solids
WGK 3 highly water endangering
9 Carcinogenic compounds and flammable compounds labelled "Highly toxic" or "Toxic": container F. Alkyl sulfates are carcinogenic; Take particular care to avoid inhalation and skin contact. To neutralize alkyl sulfates, add dropwise (from a dropping funnel) to concentrated ice-cool Ammonia solution (Cat.No. 105426) with vigorous stirring. Before placing in container D, check the pH with pH Universal indicator strips (Cat.No. 109535).
Dangerous for the environment
Categories of danger
harmful, carcinogenic, irritant, dangerous for the environment
R 22-40-41-50/53 Harmful if swallowed.Limited evidence of a carcinogenic effect.Risk of serious damage to eyes.Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
S 26-36/37/39-46-60-61 In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.Wear suitable protective clothing, gloves and eye/face protection.If swallowed, seek medical advice immediately and show this container or label.This material and its container must be disposed of as hazardous waste.Avoid release to the environment. Refer to special instructions/ Safety data sheets.
Product Usage Statements
Storage and Shipping Information
Store at +5°C to +30°C.
Declaration (railroad and road) ADR, RID
UN 3077 , 9, III
Declaration (transport by air) IATA-DGR
UN 3077 , 9, III
Declaration (transport by sea) IMDG-Code
UN 3077 , 9, III, Marine Pollutant: P
Dye content (spectrophotometrically)
≥ 88 %
Absorption maximum λ max (water)
589 - 594 nm
Spec. Absorptivity A 1%/1cm (λmax; 0.002 g/l; water)