Prepare specimens commonly used preservative fixed drug, what the advantages and disadvantages? Phenol: names phenol, also known as carbolic acid. Phenol and ethanol is similar, but also make the protein coagulation, is a good antiseptic, but no specimens were fixed hardening effect, generally not used alone Xi'an plant specimens, mostly used in conjunction with other drugs. Disadvantages: 1. there is a bad smell, so color is poor specimen of muscle (especially cardiac) and brain specimens and other processing are not ideal. High concentrations of phenol has a strong caustic plant specimens, pay attention to protection contact. Concentrated phenol can burn the skin, such as accidentally stained, requiring immediate rubbing alcohol. Low concentrations of phenol can still make nerve endings paralysis, long-term direct contact, should take appropriate protective measures. 2. For phenol bad smell, particularly poor color samples stored disadvantage, someone phenol derivatives, pentachlorophenol sodium proposed to replace it. Bactericidal effect mildew function of sodium pentachlorophenol phenol stronger than phenol, bad smell few specimens saved Gansu color better than phenol plant specimens, tendons, fascia and other connective tissue white, yellow fat, muscle dark red to brown. Pentachlorophenol sodium concentration used is 0.25 to 1.0%, if the concentration further increase, the treated muscle specimens appears dark brown, typically 0.75% solution. Sodium pentachlorophenol usually be mixed with formaldehyde used. Phenol will corrode plexiglass Shandong plant specimens, specimens treated by phenol preservative fixative, not suitable for plexiglass package. Finishing herbarium specimens should first be taken back to sort out the larger sets of paper material according to the size of the cut foliage too long; long grasses can be folded "V" or "N" shape . Another large intercept roots, stems middle (with leaves), stems department (with leaves, flowers and fruit) to suppress three sections, but the three-part system should collect the same number plates; large leaves (monocots) by vein About half cut side (left tip and leaf base), large pinnate leaf on one side of the impeller can be cut, but the tip of the leaf can not cut; each specimen should have a few leaves of the back-up in order to Leaves were observed for both sides: the leaves can not overlap, may cut more, but to stay petioles, leaves the students to observe the situation; succulent leaves, roots, tubers, bulbs and other first with boiling water scalded to death, then cut into thin slices pushed folder, otherwise difficult to suppress; flowers should start to see the internal structure. To a large fruit sliced ??and then pressed. Tianjin plant specimens, plant specimens, teaching voyage by voyage Teaching Equipment Co., Ltd. Xinxiang City. Xinxiang City voyage Teaching Equipment Co. (www.xxyuanhang.cn) strong, credible, in Xinxiang specimen model industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the voyage into the brilliant teaching and you work for a better future!