Aqueous Nigrosin Solution: High-Quality Negative Stain for Microscopy 

In situations where accuracy and clarity are critical in microbiological research, Aqueous Nigrosin Solution emerges as a valuable staining agent. As a negative stain for microscopy, Nigrosin increases contrast by coloring the background rather than the sample. Here at Eng Scientific, we provide high-purity aqueous Nigrosin solutions in 1% and 10% concentrations, specifically designed for use in microbiology labs, histology, and cytology units.  

Whether you're staining bacterial capsules, making slides for microscopy, or performing cell viability tests, our Nigrosin solutions provide clarity, convenience, and reproducible results. Relied on in educational labs, research laboratories, and clinical labs, Eng Scientific's Nigrosin allows microorganisms to be visualized with little preparation and excellent definition.  

What is Aqueous Nigrosin Solution?  

Nigrosin, or Acid Black 2, is a laboratory dye utilized for background staining in microscopy. When dissolved in water, it's water-soluble and used mainly for negative staining applications. Rather than staining the cells themselves, it darkens the surrounding area so transparent structures such as bacterial spores or capsules can clearly be seen against a darker background.  

This method circumvents the use of heat fixation, preserving the specimen's original size, shape, and structure. That makes Nigrosin particularly beneficial where the integrity of cells is important, such as in viability tests, capsule identification, and morphological examination.  

Nigrosin's convenient formulation, coupled with its compatibility with regular light microscopy, makes it an indispensable stain for any laboratory dealing with microbiological examination.  

Why Use Nigrosin for Negative Staining?  

The main advantage of Nigrosin is that it delivers excellent contrast between the background and specimen without damaging or changing the sample. This comes in especially handy when working with:  

• Encapsulated bacteria, such as Klebsiella pneumoniae or Streptococcus pneumoniae   
• Live vs. dead cell discrimination in viability studies  
• Spores, flagella, and other fragile cell structures   
• Educational laboratories, where safe, low-prep stains are critical for demonstrations  

Nigrosin is a quick, no-heat staining technique that is safe and efficient for most general light microscopy purposes.  

Concentrations Available at Eng Scientific  

We supply Nigrosin solutions at two laboratory-standard concentrations at Eng Scientific:  

1% Aqueous Solution of Nigrosin  

• Great for general microbiology laboratories and everyday staining applications   
• Provides enough contrast to identify bacterial shapes, profiles, and distribution   
• Ideal for student use, academic settings, and quick microscopy prep  

10% Aqueous Nigrosin Solution  

• Preferred for capsule staining and samples needing deeper background contrast   
• Optimal for research studies, clinical pathology, and high-magnification imaging   
• Delivers enhanced background depth, highlighting translucent regions more distinctly  

Both products are delivered in 100 mL packaging, clearly marked with batch numbers and supported by extensive Safety Data Sheets (SDS) and Certificates of Analysis (COA) to guarantee compliance and traceability.  

Applications of Aqueous Nigrosin in the Lab  

Microbiology and Capsule Staining  

Nigrosin is a standard in capsule staining procedures. Because capsules are not stained by conventional dyes, the negative staining method using Nigrosin enables clear observation of the capsule as a halo surrounding the organism on a dark background. This technique is fast and sensitive for detecting virulence factors in encapsulated bacteria.  

Cell Viability and Cytology  

Used in viability tests, Nigrosin selectively penetrates non-viable (dead) cells but is excluded by live cells. This makes it an effective tool for assessing cell culture health, fermentation quality, and clinical diagnostics.  

Educational and Diagnostic Laboratories  

Nigrosin is commonly used in teaching and research laboratories because of its ease of use, reliability, and sharp contrast results. It simplifies learning in microbiology by making it easier for students to understand cell morphology, capsule visualization, and slide preparation.  

Specialized Research and Histological Stains  

Beyond routine microbiology, Nigrosin supports Dorner's spore staining method and complements other dyes for dual-staining procedures. Researchers value its flexibility across multiple staining protocols without compromising cell structure integrity.  

Why Choose Eng Scientific for Nigrosin  

With years of expertise in laboratory reagent supply, Eng Scientific is well-known among professionals in the U.S. for high-quality microscopy stains and chemicals. Our Aqueous Nigrosin solutions are:  

• Designed for optical clarity and reproducibility  
• Lab-tested for purity, solubility, and stability  
• Packaged in lab-ready 100 mL volumes  
• Delivered with professional labeling and traceable documentation  
• Accompanied by SDS and COA for every batch  
• Backed by fast U.S. shipping and expert customer support  

If you're managing an educational institution, diagnostic center, or research organization, Eng Scientific ensures your Nigrosin solution arrives on time and performs reliably.  

How to Order Aqueous Nigrosin from Eng Scientific  

Purchasing your Aqueous Nigrosin Solution from Eng Scientific is fast, secure, and customizable. Simply visit our website, go to the Nigrosin product page, pick your desired concentration (1% or 10%), choose the quantity, and complete your checkout.  

We support:  

• Bulk orders  
• Educational discounts  
• Institutional procurement  
• Recurring supply contracts  

We also offer custom quotes and technical consultations to help you choose the best Nigrosin solution for your workflow.  

Every shipment is carefully packaged to protect product integrity and includes clear labels and compliance-ready documentation.  

Conclusion  

For high-contrast, easy-to-use negative staining solutions, Eng Scientific's Aqueous Nigrosin provides unmatched consistency. Whether for capsule detection, viability testing, or academic training, our Nigrosin preparations offer the precision staining needed for today’s scientific workflows.  

Order your Aqueous Nigrosin Solution today at EngScientific.com  

Need technical support or a custom quote? We’re here to help you every step of the way.