DE2710147

A prepn. of biological objects comprises pieces of human, animal or plant tissue, which have been given an unlimited preservations by impregnation with a polymerisable plastic material, the surface outline of the pieces being substantially maintained. The objects are prepd. by imbibing them with a soln. of plastic material with or without a hardener, accelerator diluents etc. after withdrawing from the soln. a post treatment polymerisation is effected. The objects are used as specimens for examination e.g. such as human organs or plants. The process imparts to the objects easy examination and good mechanical resistance. The surface of the prepn. has a plastic layer, which is not visible, of thickness up to 0.4 mm. The refractive index of the polymerised material pref. corresponds with that of the material to be impregnated. The plastic material is pref. with a low colour value. The object may or may not be transparent. Contrasts may be made by filling voids with colour or by means of gas. Plastic materials are pref. acrylic, polyester, epoxide, polyurethane or silicone resins. The polymerisation is pref. effected on plates or sheets. Solns of plastic materials employ, ethanol, acetone, dichloromethane and air. Impregnation is pref. by perfusion, the object having a higher vapour tension than the plastic material soln. The medium is pref. evaporated and replaced by the plastic soln. The medium is pref. withdrawn as a gas by aspiration under vacuum. The impregnation is pref. carried out by perfusion, or with the acid of vacuum. The solvent is evaporated after hardening has been carried out.