Overview
Molisch's Reagent is a classical biochemical solution named after Austrian botanist Hans Molisch. It consists of α-naphthol dissolved in ethanol (95%) and is used as a preliminary screening tool for carbohydrates. The reagent reacts with all classes of carbohydrates—monosaccharides, disaccharides, and polysaccharides—producing a characteristic purple-violet ring at the interface in a positive test. The test is highly sensitive but non-specific, often followed by confirmatory assays. Its simplicity makes it a staple in educational laboratories and quality control processes in food and pharmaceutical industries.
Physical and Chemical Properties
The reagent appears as a colorless to faint yellow liquid with a distinct aromatic odor due to α-naphthol. Its density slightly exceeds water (1.10–1.12 g/cm³), and it remains stable under recommended storage conditions. The active component, α-naphthol, has limited water solubility but dissolves readily in organic solvents like ethanol. In the presence of concentrated sulfuric acid (added during testing), carbohydrates dehydrate to form furfural derivatives, which condense with α-naphthol to yield the diagnostic purple complex. This reaction occurs even with trace amounts of carbohydrates, with sensitivity down to 0.1 mg/mL.
Main Applications
Molisch's test is primarily employed in biochemistry laboratories to confirm the presence of carbohydrates in samples such as urine, plant extracts, or food products. It serves as a first-step screening before advanced analyses like HPLC or enzymatic assays. Clinical labs use it to detect abnormal carbohydrate metabolism in patients. In industrial settings, the reagent aids in quality control of sugar-containing products like syrups or starch hydrolysates. Researchers also apply it in plant physiology studies to map carbohydrate distribution in tissues. Despite its age (developed in 1886), the test remains relevant due to its cost-effectiveness and rapid results.
Safety and Storage
Molisch's Reagent requires careful handling due to the flammability of ethanol and the irritant properties of α-naphthol. Always use gloves and safety goggles, and work in a well-ventilated area. Spills should be absorbed with inert material and disposed as hazardous waste. Store the reagent in amber glass bottles at 15–25°C, tightly sealed to prevent ethanol evaporation. Shelf life typically exceeds two years if uncontaminated. Incompatible materials include strong oxidizers and acids—keep separate from sulfuric acid until actual testing. Transportation regulations may apply for bulk quantities due to ethanol content.
B2B Procurement Guide
For bulk procurement, prioritize suppliers providing certificates of analysis (CoA) specifying α-naphthol purity (≥98%) and ethanol concentration. Industrial-grade reagents suffice for routine testing, while research applications may require HPLC-verified purity. Packaging options range from 500 mL bottles to 20 L jerricans, with discounts common for >10 L orders. Lead times vary by region; ensure suppliers comply with local chemical regulations (e.g., REACH in EU, TSCA in US). Some vendors offer customized formulations with stabilizers for extended shelf life. For international shipments, confirm adherence to IATA/IMDG guidelines for flammable liquids. Sample testing before large orders is recommended to verify performance.
Related Manufacturers
- 主营：[]
- 主营：卡尔费休试剂
- 主营：[]
- 主营：[]
- 主营：[]
- 主营：[]
- 主营：硫代癸烷、棕榈酸甲酯、正辛酸甲酯、化学试剂、总镍试剂、仲丁基氯化镁、正庚基溴化镁、仲丁基溴化镁、棕榈酸异丙酯
- 主营：阻燃剂、催化剂、洗涤剂、生物试剂、硫酸铵、醋酸镧、起泡剂、清洗剂、碳酸钙、抗氧剂、灭火剂、交联剂、粘合剂、封头剂、丙二醇、酸二氢铝、聚乙烯醇、对氯溴苯、息香乙醚、异戊二醇、香精香料、4-丁二醇、2-氯丙烯腈、2-己基癸酸、二甲胺硼烷
- 主营：1-苯丙醇、1-萘甲醚、金刚烷醇、科隆试剂、罗恩试剂、阿拉丁试剂、麦克林试剂、科密欧试剂、大小化工试剂、1-溴十八烷、2-恶唑烷酮、1-甲酰哌啶、2-氟苯甲醛、2-甲基吡嗪、2-氮己环酮、1-溴金刚烷
- 主营：硫酸汞、硝酸汞、雷尼镍、钒试剂、二十烷、丁二酸、硫化银、正己醇、硫酸镉、铋酸钠、苯甲醇、硅酸钠、正辛酸、硫酸镁、磷钨酸、滑石粉、草酸锡、蓖麻油、椰子油、异辛醇
- 主营：乙醇钾、烯丙基碘、异戊酰氯、分析纯试剂、癸二酰氯、偏钒酸钾、丙二酰氯、糠基硫醇、硫代乳酸、1-乙基哌啶、n-丁基苯胺、2-环己烯酮、2-乙基吡啶、4-乙基吡啶、4-碘硝基苯、3-碘硝基苯、二丙基硫醚、碘代仲丁烷、间硝基苯胺、硫氰酸苄酯、硫氰酸甲酯、环氧溴丙烷、乙酸间甲苯酯、氯仿酸氯甲酯、重氮乙酸乙酯
- 主营：cy荧光染料、ICG吲哚菁绿、源头厂家
- 主营：磷脂聚乙二醇、胆固醇聚乙二醇、PLGA、功能化聚乙二醇、硬脂酸聚乙二醇、透明质酸、聚乙内酯、聚乳酸、葡聚糖、DOPE