61135

Crystal Violet

for microscopy (Bact., Bot., Hist., Vit.), indicator (pH 0.1-2.0)

• Synonym(s): Basic Violet 3, Gentian Violet, Hexamethylpararosaniline chloride, Methyl Violet 10B
• Linear Formula: C₂₅H₃₀N₃Cl
• CAS Number: 548-62-9
• Molecular Weight: 407.98
• Colour Index Number: 42555
• Beilstein/REAXYS Number: 3580948
• MDL number: MFCD00011750
• UNSPSC Code: 12171500
• PubChem Substance ID: 329759365
• NACRES: MA.02

Properties

• grade: for microscopy (Bact., Bot., Hist., Vit.); indicator (pH 0.1-2.0)
• Quality Level: 200
• form: powder
• technique(s): microbe id | staining: suitable
• color: green to very dark green
• visual transition interval: 0.1-2.0, yellow-green to blue-violet
• mp: 205 °C (dec.) (lit.)
• density: 1.190 g/cm³
• ε (extinction coefficient): ≥1750 at 585-595 nm in water
• suitability: suitable for microscopy (Bact., Bot., Hist., Vit.)
• antibiotic activity spectrum: fungi
• application(s): diagnostic assay manufacturing; hematology; histology
• mode of action: cell membrane | interferes; enzyme | inhibits
• storage temp.: room temp
• SMILES string: [Cl-].CN(C)c1ccc(cc1)\C(c2ccc(cc2)N(C)C)=C3/C=C\C(C=C3)=[N+](/C)C
• InChI: 1S/C25H30N3.ClH/c1-26(2)22-13-7-19(8-14-22)25(20-9-15-23(16-10-20)27(3)4)21-11-17-24(18-12-21)28(5)6;/h7-18H,1-6H3;1H/q+1;/p-1
• InChI key: ZXJXZNDDNMQXFV-UHFFFAOYSA-M

Description

General description

Crystal violet, also known as Basic Violet 3 or Gentian Violet, is a basic, cationic aminoarylmethane dye. It is the N-hexamethylated derivative of pararosaniline and bears a lipophilic cation. It is primarily used in bacteriology and microscopy as the primary stain in Gram staining to classify and distinguish between Gram-positive and Gram-negative bacteria. It is indicator grade, exhibiting a color transition from yellow-green in acidic conditions to blue-violet in basic conditions. It also possesses antibacterial and antifungal properties.

Application

• Crystal violet is mainly used in Gram staining and its variants, and for staining amyloid, bacterial components, and vascular plant tissues.
• It is used in polychrome staining of epoxy resin sections, viability staining of cultured neurons, and confocal optical sectioning to analyze meiotic structures.
• It is also employed in the acridine orange-crystal violet staining of intracellular bacteria, microsporidian spores, and cytological smears.

Biochem/physiol Actions

The antimicrobial properties of crystal violet are due to free radical generation and the formation of unionized dye-bacteria complexes. It inhibits bacterial protein synthesis and cell wall formation and is especially effective against Gram-positive bacteria.

Principle

Gram staining is used to differentiate bacteria based on their cell wall structure. Gram-positive bacteria have a thicker cell wall with more peptidoglycan and less lipid content, while gram-negative bacteria have a thinner cell wall with less peptidoglycan and more lipid content. During the staining process, crystal violet is applied to the bacteria, followed by the iodine to form a complex that fixes the dye. A decolorizer is then used to remove the dye from gram-negative bacteria by dissolving their lipid layer. Gram-positive bacteria retain the dye due to the dehydration and shrinking of their cell walls. A counterstain, such as safranin or basic fuchsin, is applied to impart a pink color to decolorized gram-negative bacteria.

Safety Information

• pictograms: GHS08,GHS05,GHS07,GHS09
• signalword: Danger
• hcodes: H302,H318,H341,H350,H410
• pcodes: P202 - P273 - P280 - P301 + P312 - P305 + P351 + P338 - P308 + P313
• Hazard Classifications: Acute Tox. 4 Oral - Aquatic Acute 1 - Aquatic Chronic 1 - Carc. 1B - Eye Dam. 1 - Muta. 2
• Storage Class: 6.1C - Combustible acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges