Fast Black K salt
Fast Black K salt (CAS 64071-86-9), with the empirical formula C14H12ClN5O4·0.5ZnCl2 and a molecular weight of 417.88, is a diazonium salt used primarily as a stain and dye. Its distinct colour index (37190) and absorption maximum at 457 nm make it valuable in specific staining procedures. This compound is an essential reagent in cell biology, hematology, and histology, contributing to detailed microscopic analysis.
- IUPAC
- 2,5-Dimethoxy-4-(4-nitrophenylazo)benzenediazonium chloride zinc double salt,4-Amino-2,5-dimethoxy-4′-nitroazobenzene diazotated zinc double salt,Azoic Diazo No. 38
- Synonyms
- 2,5-Dimethoxy-4-(4-nitrophenylazo)benzenediazonium chloride zinc double salt4-Amino-2,5-dimethoxy-4′-nitroazobenzene diazotated zinc double saltAzoic Diazo No. 38

Histological Staining
Fast Black K salt serves as a vital component in differential staining techniques within histology. It aids in the visualisation of specific cellular or tissue structures, enhancing diagnostic capabilities in microscopic examination.
Cell Biology Research
In cell biology, this compound is employed for staining purposes to identify and study cellular components. Its use supports research into cellular morphology and function.
Hematological Analysis
As a stain for hematology, Fast Black K salt assists in the differentiation of blood cells. This is crucial for diagnosing various blood disorders and monitoring patient health.
Dye Applications
Beyond biological staining, Fast Black K salt functions as a dye in various laboratory and industrial applications where specific colouration is required. Its properties are suitable for applications demanding precise colour outcomes.
| Molecular weight | 417.88 |
|---|---|
| Empirical formula | C14H12ClN5O4 · 0.5ZnCl2 |
| Melting point | 150 °C (dec.)(lit.) |

Hazard statements
- H319Causes serious eye irritation
Precautionary statements
- P305IF IN EYES
| Protective equipment | dust mask type N95 (US), Eyeshields, Gloves |
|---|---|
| Water hazard class (WGK, DE) | 3 |
| Hazard codes (EU) | Xi |
| Risk statements (R) | 36 |
| Safety statements (S) | 26-36 |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
| Colour Index Number | 37190 |
|---|---|
| Absorption | λmax 457 nm |
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Fast Black K salt used for?
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Fast Black K salt is primarily used as a stain and dye in cell biology, hematology, and histology for microscopic examination and analysis. It is also applied in other dye applications requiring precise colouration.
What are the CAS number and formula for Fast Black K salt?
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The CAS number for Fast Black K salt is 64071-86-9. Its empirical formula is C14H12ClN5O4 · 0.5ZnCl2.
What grade and purity does Tech Serve Solutions supply?
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Tech Serve Solutions supplies Fast Black K salt with specified purity suitable for laboratory research. The exact assay is available on the product's Certificate of Analysis. We do not represent this product as USP, BP, or EP grade.
How should Fast Black K salt be handled safely?
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Fast Black K salt is a warning substance that causes serious eye irritation (H319). Handle with appropriate personal protective equipment including a dust mask type N95 (US), eyeshields, and gloves. Ensure good ventilation and avoid dust formation.
How is Fast Black K salt packed, shipped, and exported?
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Fast Black K salt is carefully packed to maintain its integrity during transit. Tech Serve Solutions is experienced in exporting fine chemicals globally, adhering to all relevant shipping and customs regulations.
How can I request a sample or quote for Fast Black K salt?
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To request a sample or a quotation for Fast Black K salt, please contact our sales team through the website or by phone, providing your contact details and the quantity required.
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