Prepare specimens commonly used preservative fixed drug, what the advantages and disadvantages? Alcohol: Ethanol scientific name, the chemical structure of formula CH3CH2OH. Is a colorless liquid, boiling point 78.3 ℃, volatile, accounting for 0.80 Xi'an plant specimens, with carbolic acid, glycerin, water any mix, is a good solvent. Advantages: Alcohol has a strong dehydration plant specimens Gansu, can the cell surface and internal moisture removal. So that the molecular structure of the protein release, and protein denaturation and coagulation. This is the alcohol sterilization, conservation organizations, the basic principles of preventing corruption. Alcohol in tissue permeability, mixing alcohol preservative was added, can enhance penetration, shorten corrosion fixed time. Specimens fixed with alcohol, color preserved, not strong irritant, no bad smell. Disadvantages: a high concentration of alcohol, enabling the rapid degeneration of the cell surface protein coagulation, forming a protective film, but to stop the drug into the deep play. Therefore, the fixed specimens alcohol concentration Hebei plant specimens, generally should not exceed 75% (volume percent) 2. dehydration too, specimen shrinkage, up to about 20%, and can dissolve fat and lipids. Thus, lipid rich organs such as the brain specimens, do not use alcohol fixative. Another drawback is that it's volatile fast, easy loss. Prepare specimens commonly used preservative fixed drug, what the advantages and disadvantages? Formaldehyde: aka ants aldehyde, is a colorless gas with a strong odor stimulation, soluble in water, its 35 to 40% aqueous solution of a trade name is usually called formalin. Advantages: Formaldehyde easily with protein amino combine to make the protein coagulation, gelatin coagulation, tissue fixation, but also save fat and lipids, permeability strong, shrinkage small, inexpensive to maintain the position of the specimen form and maintain a good skin color plant specimens, is an excellent, the most widely used preservative fixative. Cons: The fixed tissue stiff brittle, easily pulled off the muscle fibers, inconvenience anatomy operate; there is a strong irritant, eye conjunctiva, respiratory tract and frequent contact with the skin have some damage. Beijing plant specimens _ voyage teaching (certified) _ plant specimens provided by Xinxiang City Teaching Equipment Co. voyage. Xinxiang City voyage Teaching Equipment Co. (www.xxyuanhang.cn) is an industry leader in Henan Xinxiang, specimen model years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. On the voyage instructional leadership with the staff warmly welcome all inquiries negotiations to create a better future teaching voyage.