正品现货|XLT4 Agar Base|XLT4琼脂基础 原理: XLT4 Agar Base contains peptone as a source of complex nitrogen compounds. Yeast extract is added as a source of vitamins and other cofactors. Differentiation of Salmonella from other organisms that also grow on this medium is based on fermentation of xylose, lactose and sucrose,decarboxylation of lysine and the production of hydrogen sulfide. Hydrogen sulfide production is detected by the addition of ferric ions. Sodium thiosulfate is added as a source of inorganic sulfur. Sodium chloride maintains the osmotic balance of the medium. Agar is the solidifying agent. Phenol red is added as an indicator of pH changes resulting from fermentation and decarboxylation reactions. XLT4 Agar Supplement is added to inhibit growth of non-Salmonella organisms. Directions for Preparation from Dehydrated Product 1. Suspend 59 g of the powder in 1 L of purified water. 2. Add 4.6 mL XLT4 Agar Supplement. Mix thoroughly. 3. Heat with frequent agitation and boil for 1 minute to com- pletely dissolve the powder. Avoid overheating. DO NOT AUTOCLAVE. 4. Test samples of the finished product for performance using stable, typical control cultures. 过程: 1. Inoculate a suitable Salmonella enrichment broth (such as Tetrithionate Broth) and incubate at 35°C for 18-24 hours. 2. Following enrichment, subculture onto XLT4 Agar. Streak for isolation. 3. Incubate plates aerobically at 35 ± 2°C. Examine for growth after 18-24 and 48 hours incubation. 用途: XLT4 Agar Base is used with XLT4 Agar Supplement in isolating non-typhi Salmonella. |