Fixativen

Fixativen are substances used to stabilize surfaces or samples to prevent deterioration or unwanted change. They are employed in art conservation, biological specimen preparation, and photography, among other fields. Depending on the application, fixativen act by forming chemical bonds, sealing porous materials, or removing unfixed components.

In art, fixativen protect drawings and pastels from smudging and abrasion. They can be solvent-based or water-based and are typically sprayed in light, even coats. While helpful, fixativen may alter color, gloss, or surface feel and may not be fully archival. For this reason artists select products with pH-neutral formulations and test compatibility with pigments.

In biology and histology, fixativen preserve tissue structure for examination under light or electron microscopy. Common fixativen include formaldehyde (including formalin), paraformaldehyde, and glutaraldehyde, often used in buffered, isotonic solutions. Fixation fixes proteins by cross-linking and helps immobilize lipids and cellular components. Some fixativen preserve antigenicity differently, and fixation artifacts can occur. Electron microscopy often requires osmium tetroxide after aldehyde fixation.

In photography, fixers (not always called fixativen) dissolve unexposed silver halide from photographic film or print after development, stabilizing the image. The standard fixer is a thiosulfate compound (sodium thiosulfate or ammonium thiosulfate). Proper washing and disposal are important.

Safety and handling: many fixativen are hazardous, irritants, or toxic. Use in well-ventilated areas, wear gloves and eye protection, and follow handling and storage guidelines. Dispose of waste according to local regulations.