| 培養基名稱 |
去氧膽酸鹽檸檬酸鹽瓊脂 去氧膽酸鹽枸櫞酸鹽瓊脂 |
|---|---|
| 英文名稱: |
Desoxycholate Citrate Agar DCA Medium |
| 產品目錄號: | M705-01 |
| 產品規格: |
500g 其它規格請聯系我們 |
| 保存條件: | 密封，陰涼干燥處保存。 |
| 產品性狀: |
米色或淺粉色粉末，易吸潮。溶液呈橘紅色，透明或略渾濁。 |
| 注意事項: |
避免攝入、呼入、皮膚接觸。配制時在通風櫥中進行， 戴口罩、手套、護目 鏡。 |
產品描述：
去氧膽酸鹽檸檬酸鹽瓊脂（Desoxycholate Citrate Agar）簡稱DCA培養基，用于分離腸道致病菌，尤其是沙門氏菌和志賀氏菌。檸檬酸鐵銨被硫化氫還原，使得菌落中心變黑。
去氧膽酸鹽檸檬酸鹽瓊脂應該與其它選擇性培養基如麥康凱瓊脂、亞硫酸鉍瓊脂、煌綠瓊脂、煌綠2%膽鹽肉湯、非選擇型的血瓊脂培養基共同使用。
去氧膽酸鹽檸檬酸鹽瓊脂應該與其它選擇性培養基如麥康凱瓊脂、亞硫酸鉍瓊脂、煌綠瓊脂、煌綠2%膽鹽肉湯、非選擇型的血瓊脂培養基共同使用。
本產品是采用的是典型去氧膽酸鹽檸檬酸鹽瓊脂配方。
去氧膽酸鹽檸檬酸鹽瓊脂培養基的用途 ：
DCA培養基用于分離腸道致病菌，尤其是沙門氏菌和志賀氏菌。
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.
| 腸炎沙門氏菌 | ATCC13076 | 生長良好 | 土黃色菌落，有黑色中心 |
| 傷寒沙門氏菌 | ATCC14028 | 生長良好 | 土黃色菌落，有黑色中心 |
| 諾丁漢沙門氏菌 | NCTC7832 | 生長良好 | 土黃色菌落，有黑色中心 |
| 索氏志賀氏菌 | ATCC25931 | 生長良好 | 土黃色菌落 |
| 福氏志賀氏菌 | ATCC12022 | 生長良好 | 土黃色菌落 |
沙門氏菌與志賀氏菌在DCA培養基上的菌落形態
索氏志賀氏菌菌落形態——DCA培養基
去氧膽酸鹽檸檬酸鹽瓊脂（Hynes）培養基配方 ： 1L
牛肉浸粉 ................5.0 g
蛋白胨 ..................5.0 g
乳糖 ....................10.0 g
檸檬酸鈉 ................5.0 g
硫代硫酸鈉 ..............5.0 g
檸檬酸鐵銨 ..............1.0 g
去氧膽酸鈉 ..............2.5 g
中性紅 ..................0.025 g
瓊脂 ....................15.0 g
pH 7.0±0.2
配制方法：
1. 稱取48.5g去氧膽酸鹽檸檬酸鹽瓊脂，加1000 mL超純水，在火焰上方加熱煮沸完全溶解。不要高溫蒸汽滅菌。過度加熱會使培養基失效。
2. 冷卻至50度左右時，倒平板。待干燥后使用。
相關產品