4% formaldehyde, commonly known as 10% formalin, is an essential fixative in the field of histopathology. This product is fundamental for the preservation and analysis of biological samples, thanks to its ability to inactivate autolytic enzymes and the bacteria responsible for tissue putrefaction. Formaldehyde provides structural stability to the chemical components of the protoplasm, ensuring reliable results in histological analyses.

Main Features

• Primary Non-Coagulant Fixative: 4% formaldehyde hardens protein gels without separating water from proteins, preserving cellular structure.


• Rapid Penetration: Thanks to its low oxidation potential, formaldehyde penetrates tissues quickly, ensuring gradual and uniform hardening.


• Fixation Ratio: The ideal volumetric ratio between the tissue to be fixed and the fixation liquid is about 1:20, to ensure effective fixation.


• Customizable Fixation Time: The time required for fixation must be assessed by the operator based on the volume and type of sample, thus ensuring optimal results.

Product Composition

4% formaldehyde is composed of:

• Formaldehyde (3.80% ÷ 4.40%)


• Methanol < 0.1%


• Disodium phosphate


• Monosodium phosphate


• Deionized water

The buffer molarity is 75 millimoles/liter, with a pH of 7 ± 0.1, thus ensuring a stable environment for sample fixation.

Applications of 4% Formaldehyde

This fixative is widely used in various fields, including:

• Histology Laboratories: For preparing samples for microscopic analysis.


• Biomedical Research: In the preservation of tissues and cells for scientific studies.


• Medical Diagnostics: In the preparation of samples for pathological diagnoses.

Warnings and Safety

It is important to handle formaldehyde with caution, following appropriate safety guidelines. Be sure to use personal protective equipment (PPE) and work in a well-ventilated area to minimize exposure.

Choose 4% formaldehyde to ensure high-quality results in your histological analyses and effective preservation of biological samples.