Aniline Blue, C.I. 42755 (Acid Blue 22), is a certified, water-soluble biological stain used in histology and cytology. In trichrome staining methods, aniline blue serves as an acid dye component for differential visualization of connective tissue, including collagen.
Applications include Mallory connective tissue staining, histological and cytological contrast staining, and selected plant histochemistry methods. This grade has an assay of ≥90% and a λmax specification of 594–610 nm.
Synonyms: C.I. Acid Blue 22; Aniline Blue W.S.; Water Blue.
Key Properties
- Certified, water-soluble biological stain
- C.I. number: 42755
- Common dye designation: Acid Blue 22
- CAS number: 28631-66-5
- Assay: ≥90%
- λmax: 594–610 nm
- Appearance: shiny brown crystalline powder
- Staining performance: satisfactory in Biological Stain Commission tests
- pH indicator range: 10.0–13.0
- Storage temperature: room temperature
- Polysciences catalog number: 02570
Applications
Histology & Cytology Contrast Staining
Aniline Blue is used as a contrast stain in histological and cytological methods. Staining characteristics depend on tissue preparation, fixation, solution composition, pH, staining sequence, and differentiation conditions.
Mallory Connective Tissue Staining
Aniline Blue is a component of Mallory connective tissue staining and is used with acid fuchsin and other reagents in the complete trichrome method. The technique differentiates connective-tissue components, with collagen characteristically appearing blue under appropriately controlled staining conditions.
Plant Callose Visualization
Aniline blue preparations are used in fluorescence-based methods for detecting callose, a β-1,3-glucan found in plant cell walls and associated structures. When using Aniline Blue for callose studies, staining and imaging conditions should be validated for the specimen and experimental method.
pH Indicator
Aniline Blue can also be used as a colorimetric pH indicator in the alkaline range of approximately pH 10.0–13.0. Indicator performance should be evaluated under the conditions of the specific analytical method.
Application Tips
- Prepare working solutions according to the validated staining or analytical method
- Standardize dye concentration, staining time, pH, and differentiation conditions when comparing specimens
- Follow the complete reagent sequence when using Aniline Blue in Mallory or other multicomponent staining procedures
- Use consistent staining and imaging conditions for fluorescence-based callose measurements
- Do not interpret the reported λmax of 594–610 nm as a fluorescence excitation/emission pair
- Review lot-specific documentation when staining performance or certification status is critical to the method
Handling & Storage
- Store at room temperature in a cool, well-ventilated location
- Keep the container tightly closed when not in use
- Handle with adequate laboratory ventilation or in a chemical fume hood
- Minimize generation and inhalation of dye dust
- Wear protective gloves, safety glasses, and suitable protective clothing
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FAQ
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1. What is Aniline Blue used for?
Aniline Blue is used as a biological stain in histology and cytology, including connective-tissue staining methods such as Mallory’s stain. Aniline blue preparations are also used in plant research for fluorescence-based visualization of callose.
2. What structures does Aniline Blue stain?
The staining target depends on the method. In Mallory and related trichrome procedures, Aniline Blue contributes to blue staining of collagen and other connective-tissue components. In specialized plant fluorescence methods, aniline blue preparations are used to visualize callose.
3. Is Aniline Blue the same as aniline?
No. Aniline Blue is the name of a biological dye or related group of blue dyes. Aniline is a different, low-molecular-weight aromatic amine. Searches concerning the solubility or properties of aniline should not be applied to Aniline Blue.
4. Is C.I. 42755 the same as Acid Blue 22?
Yes. C.I. 42755 is also known as Acid Blue 22. This water-soluble Aniline Blue grade is identified by CAS number 28631-66-5.
5. Is this Aniline Blue water-soluble?
Yes. Catalog 02570 is the water-soluble form of Aniline Blue. Prepare working concentrations and staining solutions according to the applicable laboratory method.
6. What does certified Aniline Blue mean?
Biological-stain certification is based on lot-specific chemical and staining-performance testing. This grade is evaluated using Biological Stain Commission criteria, and the product specification requires satisfactory performance in the applicable staining tests.
7. What spectral specification is reported for Aniline Blue?
The product specification reports a λmax of 594–610 nm. This value should not be interpreted as a fluorescence excitation and emission pair; fluorescence conditions depend on the staining method and dye preparation.
8. What package size is available?
Aniline Blue, C.I. 42755 is available in a 25 g package. For larger quantities, use the bulk-quote option.
Safety & Documentation
Aniline Blue can cause skin and serious eye irritation and may cause respiratory irritation. Minimize dust generation and use appropriate laboratory ventilation, gloves, and eye protection. Refer to the Safety Data Sheet, product specification, and lot-specific documentation for complete handling, storage, disposal, and quality information.
