Whitening preparation
Lightening preparations are transparent macroscopic preparations in which one can study selectively colored tissue or cavity systems.
Procedure
In the case of specimens for which no demonstration of the bones is desired, these are first dissolved by decalcification. The eponymous “lightening” is nothing more than a simple bleaching of the preparations with hydrogen peroxide . The effect of transparency is based on the equalization of the refractive index of the storage solution with that of the preparation. When the refractive indices approach, the light in the specimen (at the boundaries of the solid tissue and the solution) refracts less and less, and the color of the specimen changes from opaque white to translucent to completely transparent. The process is also known as the split wood method, and specimens treated in this way are also called split wood preparations, according to Werner Spalteholz (1861–1940), Prosector at the Leipzig Anatomical Institute.
The previous differentiation of individual tissues is done by coloring (bone nuclei, cartilage, nerves ...) or by not decalcifying (bones). Hollow systems are represented by injection ( blood vessels , bile ducts ).
The storage solution can now also be replaced by polymerizable plastic resins, if the resins have a corresponding refractive index, which z. B. is the case with individual epoxy and polyester resins . Such embedding preparations are much more robust than preparations in sensitive glasses.
Individual evidence
- ↑ Werner Spalteholz : About making human and animal preparations transparent and its theoretical conditions. Along with appendix: About bone staining. Hirzel, Leipzig 1914, 91 pp.