Basic Fuchsin (pararosaniline hydrochloride), C.I. 42500, is an aminotriarylmethane dye used in histological and bacteriological staining. This certified stain is particularly relevant to methods requiring pararosaniline, including Schiff reagent and Feulgen workflows, and is also used in staining procedures for bacilli and in enzyme-histochemical methods involving esterase localization.
Synonyms: Pararosaniline hydrochloride; Basic Red 9; Basic Fuchsin; Parafuchsin; Pararosaniline chloride.
Key Properties
- Catalog number: 06342
- Colour Index number: C.I. 42500
- CAS Number: 569-61-9
- Chemical identity: Pararosaniline hydrochloride
- Chemical class: Aminotriarylmethane dye
- Molecular formula: C19H18ClN3
- Molecular weight: 323.83 g/mol
- λmax: 542–548 nm
- Grade: Certified biological stain
- Storage: Room temperature
- Available size: 25 g
Applications
Histology & Schiff/Feulgen Methods
Pararosaniline is used in histochemical workflows requiring basic fuchsin chemistry and is a defined dye component for preparation of Schiff reagent. These methods include Feulgen staining and other aldehyde-dependent histochemical procedures when specified by the validated protocol.
Bacteriological Staining
Basic fuchsin dyes are used in bacteriological staining procedures, including methods for visualization of bacilli. The Biological Stain Commission recognizes pararosaniline, C.I. 42500, for bacteriological staining and media applications.
Esterase Localization
Polysciences documents this reagent for use as a coupling agent in methods for ultrastructural localization of esterases.
Staining & Method Considerations
- Basic fuchsin is a general name that may describe mixtures of related aminotriarylmethane dyes; this Polysciences product is identified specifically as pararosaniline hydrochloride, C.I. 42500
- When a protocol specifically requires pararosaniline rather than a mixed basic fuchsin preparation, verify the dye identity and current lot documentation before use
- Schiff, Feulgen, bacteriological, and enzyme-histochemical procedures should be performed according to the validated method used by the laboratory
- Do not assume interchangeability with rosaniline-containing Basic Fuchsin, C.I. 42510, or with Basic Fuchsin specifically certified for flagella staining
- For comparative staining studies, maintain consistent fixation, reagent preparation, staining time, differentiation, and imaging conditions
Application Tips
- Use freshly prepared working solutions when required by the staining protocol
- Follow the prescribed reagent concentrations and reaction times for Schiff or Feulgen methods
- Include an appropriate positive control when evaluating staining performance
- For bacteriological staining, use the formulation and differentiation conditions specified by the validated method
- Consult lot-specific documentation when BSC certification is a procurement or method requirement
Handling & Storage
- Store at room temperature with the container tightly closed
- Wear protective gloves and chemical goggles during handling
- Avoid generating or inhaling dye dust during weighing and solution preparation
- Use appropriate laboratory ventilation and follow the current Safety Data Sheet
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FAQ
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1. What is Basic Fuchsin, C.I. 42500?
This product is pararosaniline hydrochloride, an aminotriarylmethane dye also known as Basic Red 9. Its Colour Index number is C.I. 42500.
2. What is the CAS number for this Basic Fuchsin?
The CAS number for pararosaniline hydrochloride, C.I. 42500, is 569-61-9.
3. Is Basic Fuchsin the same as pararosaniline?
The name Basic Fuchsin can refer to mixtures of several related dyes. This Polysciences product is specifically identified as pararosaniline hydrochloride, C.I. 42500.
4. What is Basic Fuchsin used for?
Basic Fuchsin and pararosaniline are used in histology and bacteriology, including Schiff and Feulgen methods and staining procedures for bacilli. Polysciences also documents this reagent for esterase-localization methods.
5. Can this product be used to prepare Schiff reagent?
Yes. Pararosaniline is used in the preparation of Schiff reagent. Follow the specific formulation and quality requirements of the validated laboratory method.
6. Is this product suitable for Feulgen staining?
Pararosaniline, C.I. 42500, is recognized by the Biological Stain Commission for the Feulgen reaction. Follow the laboratory's validated staining protocol and current lot documentation.
7. Is this Basic Fuchsin specifically a flagella stain?
No specific flagella-grade claim should be assumed for this product. The Biological Stain Commission treats Basic Fuchsin certified specifically for flagella staining as a separate certification category.
8. What is the spectral maximum of this product?
Polysciences specifies a λmax of 542–548 nm.
9. Is certification lot-specific?
Yes. Biological stain certification is associated with individual tested lots. Consult the current product documentation or certificate when certification status is required for procurement or method validation.
10. What package size is available?
Polysciences catalog 06342 is supplied in a 25 g package.
Safety & Documentation
Use appropriate laboratory ventilation and personal protective equipment when handling Basic Fuchsin. Polysciences lists this material as an irritant and expected carcinogen. Refer to the current Safety Data Sheet and lot-specific product documentation for complete handling, storage, hazard, and certification information.
