Flotation Baths in Histology: Ensuring Perfect Tissue Preparation

Flotation baths are essential tools in pathology and histology laboratories. They aid researchers and technicians in the precise preparation of tissue samples. These baths are specifically designed to float and stretch paraffin-embedded tissue sections, ensuring they are perfectly flat before being placed on microscope slides for examination. Let’s explore flotation baths, how they work, and their significance in the laboratory setting.

What Is a Flotation Bath?

A flotation bath is a laboratory device filled with water and maintained at a controlled temperature, usually between 40°C and 50°C. It is used during the microtomy process when thin tissue sections are cut from a paraffin block using a microtome. The sections are floated on the warm water in the bath, allowing them to spread out and eliminating any wrinkles or folds caused during the slicing process.

How Does It Work?

The process involves:

1. Cutting Tissue Sections: Thin tissue slices, often just a few micrometres thick, are cut from a paraffin-embedded block using a microtome.
2. Floating on Water: The sections are gently transferred to the warm water in the flotation bath. The warmth softens the paraffin, allowing the tissue to relax and flatten. To achieve the best results, distilled water should be used. Adding 95% alcohol to the water can help lower surface tension and remove wrinkles. Additionally, adhesives may sometimes be added to improve slide adhesion.
3. Mounting on Slides: Once flat, the tissue sections are carefully lifted from the water and mounted onto microscope slides, ready for staining and analysis.

Flotation baths, sometimes spelt floatation baths, are typically made of materials like stainless steel or high-grade polymers, ensuring durability and easy cleaning. Many models also feature black or dark backgrounds to improve visibility, making it easier to spot and handle delicate tissue sections.

Key Features of a Flotation Bath

Modern flotation baths are equipped with features to enhance accuracy and ease of use, such as:

• Digital Temperature Control: Precise temperature regulation is critical to avoid overheating, which can damage delicate tissue samples.
• Ergonomic Design: A wide surface area for floating sections and easy slide handling.
• High Visibility: Dark interiors or LED lighting to enhance contrast and visibility of tissue sections.

Optimising Temperature for Tissue Flotation Baths

The temperature of a flotation bath should be optimised depending on the sample type and the paraffin used. For most applications, the ideal temperature is 40°C–50°C, which is typically 5°C–10°C below the melting point of paraffin. This temperature is ideal for softening the paraffin without causing disintegration. However, certain tissues and paraffins require adjustments:

• Fatty tissues (e.g., brain or breast tissues): Require lower temperatures to prevent damage.
• Hard paraffins: Require higher water temperatures to ensure proper softening and stretching.

Maintaining the correct temperature is critical to ensure tissue sections are not damaged or distorted during the process.

Applications of Flotation Baths

Flotation baths are indispensable in the following fields:

1. Histology: Preparing tissue samples for microscopic examination to diagnose diseases such as cancer.
2. Pathology: Analyzing tissues to study diseases and abnormalities.
3. Research Laboratories: Conducting studies on biological tissues for medical and scientific purposes.
4. Education: Teaching students proper tissue preparation techniques.

Why Temperature Matters

Maintaining the correct water temperature in the flotation bath is crucial. If the water is too hot, it can damage or distort the tissue sections. On the other hand, water that is too cool won’t adequately soften the paraffin, making it difficult to flatten the tissue. The type of paraffin and tissue being used should always guide the temperature settings for optimal results.

Thermoline’s Range of Flotation Baths

At Thermoline, we understand the critical role flotation baths play in laboratories. Our flotation baths are designed with precision and reliability in mind, featuring advanced temperature controls, durable construction, and user-friendly designs. Whether you’re working in a hospital pathology lab or a research institution, Thermoline’s flotation baths provide the consistency and quality you need for optimal results.

Conclusion

Flotation baths may seem like a small piece of equipment, but their role in ensuring accurate tissue preparation is invaluable. By providing a simple yet effective way to flatten tissue sections, these water baths help deliver reliable diagnostic results and support critical medical research.

If you’re looking to upgrade your lab equipment, explore Thermoline’s range of high-quality flotation baths and experience precision like never before. Contact us today to learn more!