This invention relates to a liquid-based composition consisting of a mixture of methylethylketone peroxide between 30 and 40%, Methylethylketone between 0 and 5%, hydrogen peroxide between 0 and 5%, diisobutrate of 1-Isopropyl-2,2-Dimethyltrimethylene between 40 and 50% and Diacetone alcohol between 5 and 10%, isobutyl alcohol and glycerol and its use for the fixation and/or conservation of organic material such as isolated organs and tissues, cells of animal or vegetable origin. The invention also relates to a method for the embalming of corpses comprising the injection of such composition into the blood and/or lymphatic vascular system of an animal or vegetable organism.