| 培养基名称 |
去氧胆酸盐柠檬酸盐琼脂 去氧胆酸盐枸橼酸盐琼脂 |
|---|---|
| 英文名称: |
Desoxycholate Citrate Agar DCA Medium |
| 产品目录号: | M705-01 |
| 产品规格: |
500g 其它规格请联系我们 |
| 保存条件: | 密封，阴凉干燥处保存。 |
| 产品性状: |
米色或浅粉色粉末，易吸潮。溶液呈橘红色，透明或略浑浊。 |
| 注意事项: |
避免摄入、呼入、皮肤接触。配制时在通风橱中进行， 戴口罩、手套、护目 镜。 |
产品描述：
去氧胆酸盐柠檬酸盐琼脂（Desoxycholate Citrate Agar）简称DCA培养基，用于分离肠道致病菌，尤其是沙门氏菌和志贺氏菌。柠檬酸铁铵被硫化氢还原，使得菌落中心变黑。
去氧胆酸盐柠檬酸盐琼脂应该与其它选择性培养基如麦康凯琼脂、亚硫酸铋琼脂、煌绿琼脂、煌绿2%胆盐肉汤、非选择型的血琼脂培养基共同使用。
去氧胆酸盐柠檬酸盐琼脂应该与其它选择性培养基如麦康凯琼脂、亚硫酸铋琼脂、煌绿琼脂、煌绿2%胆盐肉汤、非选择型的血琼脂培养基共同使用。
本产品是采用的是典型去氧胆酸盐柠檬酸盐琼脂配方。
去氧胆酸盐柠檬酸盐琼脂培养基的用途 ：
DCA培养基用于分离肠道致病菌，尤其是沙门氏菌和志贺氏菌。
Escherichia coli - Most strains are inhibited, but the few strains which grow produce pink umbilicated colonies 1-2mm in diameter which may be surrounded by a zone of precipitation.
Shigella sonnei - the colonies are 1mm diameter after 18 hours incubation, and 2mm after 38 hours; they are smooth and initially colourless, becoming pale pink on further incubation due to late lactose fermentation.
Shigella flexneri - colonies are colourless and similar in appearance to those of Shigella sonnei, but often with a narrow plane periphery round a central dome.
Salmonella paratyphi B - from 1mm diameter after 18 hours incubation to 2-4mm on the second day, when they are slightly opaque, dome-shaped, with a central black dot.
Salmonella typhi - 0.25-1mm in diameter after 18 hours and pale pink, a day later they are flat, conical, 2mm in diameter, colourless and slightly opaque, often with a central grey dot.
Other Salmonella colonies - similar to those of Salmonella paratyphi B. Non-pathogenic non-lactose fermenters, such as Proteus and Pseudomonas species, grow on the medium and may produce colonies which closely simulate those of the salmonellae or shigellae. Proteus colonies are often glossy (more translucent than those of the pathogens), with a large central black dot and a "fishy" odour.
Shigella sonnei - the colonies are 1mm diameter after 18 hours incubation, and 2mm after 38 hours; they are smooth and initially colourless, becoming pale pink on further incubation due to late lactose fermentation.
Shigella flexneri - colonies are colourless and similar in appearance to those of Shigella sonnei, but often with a narrow plane periphery round a central dome.
Salmonella paratyphi B - from 1mm diameter after 18 hours incubation to 2-4mm on the second day, when they are slightly opaque, dome-shaped, with a central black dot.
Salmonella typhi - 0.25-1mm in diameter after 18 hours and pale pink, a day later they are flat, conical, 2mm in diameter, colourless and slightly opaque, often with a central grey dot.
Other Salmonella colonies - similar to those of Salmonella paratyphi B. Non-pathogenic non-lactose fermenters, such as Proteus and Pseudomonas species, grow on the medium and may produce colonies which closely simulate those of the salmonellae or shigellae. Proteus colonies are often glossy (more translucent than those of the pathogens), with a large central black dot and a "fishy" odour.
| 肠炎沙门氏菌 | ATCC13076 | 生长良好 | 土黄色菌落，有黑色中心 |
| 伤寒沙门氏菌 | ATCC14028 | 生长良好 | 土黄色菌落，有黑色中心 |
| 诺丁汉沙门氏菌 | NCTC7832 | 生长良好 | 土黄色菌落，有黑色中心 |
| 索氏志贺氏菌 | ATCC25931 | 生长良好 | 土黄色菌落 |
| 福氏志贺氏菌 | ATCC12022 | 生长良好 | 土黄色菌落 |
沙门氏菌与志贺氏菌在DCA培养基上的菌落形态
索氏志贺氏菌菌落形态——DCA培养基
去氧胆酸盐柠檬酸盐琼脂（Hynes）培养基配方 ： 1L
牛肉浸粉 ................5.0 g
蛋白胨 ..................5.0 g
乳糖 ....................10.0 g
柠檬酸钠 ................5.0 g
硫代硫酸钠 ..............5.0 g
柠檬酸铁铵 ..............1.0 g
去氧胆酸钠 ..............2.5 g
中性红 ..................0.025 g
琼脂 ....................15.0 g
pH 7.0±0.2
配制方法：
1. 称取48.5g去氧胆酸盐柠檬酸盐琼脂，加1000 mL超纯水，在火焰上方加热煮沸完全溶解。不要高温蒸汽灭菌。过度加热会使培养基失效。
2. 冷却至50度左右时，倒平板。待干燥后使用。
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