| 產品名稱： | 抗生素測定培養基M；拉沙里菌素測定培養基 |
|---|---|
| 英文名稱： | Antibiotic Assay Medium M |
| 培養基類型： | 非選擇性培養基 |
| 級別： | for microbiology |
| 品牌： | ELITE-MEDIA（艾禮培養基） |
| 產品目錄號： | M296-01、M296-02 |
| 產品規格： | 250g、500g |
| 產品外觀： | 麥秸色粉末。 |
| 滅菌后顏色與澄清度： | 淺黃色略不透明凝膠。 |
| 保存條件： | 密封，2-25°C保存。 |
| 注意事項： | 避免攝入、吸入、皮膚接觸。 |
| 相關產品： | -- |
產品描述：
抗生素測定培養基M（Antibiotic Assay Medium M，AOAC）作為底層瓊脂，利用枯草芽孢桿菌ATCC6633（Bacillus subtilis ATCC6633），結合瓊脂擴散法測定飼料中拉沙里菌素（Lasalocid）效價。本配方為AOAC推薦配方。用途：
抗生素測定培養基M被AOAC推薦用于微生物法測定測定飼料中拉沙里菌素效價。配方與配制方法
| 成分 | g/L |
|---|---|
| 磷酸氫二鉀 | 0.69 |
| 磷酸二氫鉀 | 0.45 |
| 酵母提取物 | 2.5 |
| 無水葡萄糖 | 10 |
| 瓊脂 | 20 |
| 終溶液pH | 6.0± 0.2 |
配制方法：
1. 稱取33.64g本產品，用1000ml純水重懸。
2. 加熱使培養基完全溶解。
3. 121°C 滅菌15min。
4. 冷卻至45-50°C 時倒平板。
實驗方法
Prepare slant culture of Bacillus subtillis (ATCC 6633) on Assay Medium No. 1 and incubate for 16-24 hours at 37°C. Wash the growth with sterile distilled water and transfer it to surface of Assay Medium No. 32 and incubate at 37°C for 7 days. Wash the growth with sterile distilled water. Heat to 65°C for 30 minutes in water bath. Centrifuge, decant the supernatant and resuspend the cells. Repeat this for 3 minutes in water bath. Dilute suspension with sterile distilled water (1 + 50) to read 20%T on sprectrophotometer at 530 nm before use.Use single inoculated agar layer. Optimum concentration of suspension of Bacillus subtillis is determined prior to assay to be added to Medium M to obtain inhibition zone of adequate size (17.5 ± 2.5 mm with 1.0 µg/ml). For actual assay add appropriate amount of suspension to sterile, molten medium M (pH 6.0). Mix and add 6 ml to each plate. Prepare plates 2.5 3 hours before use. Weigh 1.0 g premix. Transfer to flask and add 100 ml methanol. Shake vigorously for 3 minutes and dilute with methanol. Dilute 4 ml of this to 100 ml methanol. Further dilute 3 ml with 22 ml methanol and water to 100 ml (1 ml= ca/µg lasalocid Na/ml 25% methanol). Prepare final concentration of feed to 0.0075%. For more details refer AOAC.
Using lasalocid, sodium obtain standard response line, assay solution. Place cylinders on each plate and alternatively fill with reference concentration and other standard concentration. Incubate at 35-36°C. Calculate zone diameters of L (Low concentration giving measurable zone) and H (Highest concentration) of standard response line and connect with straight line. This corrected reference point is used for sample calculations. Average the 9 readings of reference concentration and 9 readings of assay solution. If assay solution gives larger average than reference concentration, add difference between them to reference point on standard response line. If the assay solution gives lower average than reference concentration, subtract the difference from reference point. Using the corrected value of assay solution, amount of antibiotic is determined.