| 培養基名稱 | 抗生素測定培養基3號；測定肉湯 |
|---|---|
| 英文名稱: | Antibiotic Assay Medium No.3；Assay Broth |
| 培養基類型: | 營養培養基 |
| 產品目錄號: | M104-01 |
| 產品規格: | 250g、500g、5kg |
| 保存條件: | 密封，陰涼干燥處保存。制備好的培養基2-8°C避光保存。 |
| 產品性狀: |
麥秸色粉末。 淺黃色透明液體。 |
| 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。 |
| 相關產品: | -- |
產品描述：
抗生素測定培養基3號(Antibiotic Assay Medium No.3)也稱測定肉湯，用于濁度法或者系列稀釋法測定很多種抗生素效價。該培養基配方按照美國藥典USP規定配制。
抗生素測定培養基3號工作原理
比濁法測定抗生素（Turbidimetric antibiotic assay）基于檢測微生物在含有均勻分布的抗生素的培養基中生長速度的改變或受抑制。該方法僅適合澄清的樣品。
蛋白胨、牛肉浸粉和酵母提取物提供重要的營養和生長因子。氯化鈉維持滲透壓平衡。磷酸鹽是緩沖劑。葡萄糖是碳源和能量來源。
抗生素測定培養基3號的用途：
推薦用于微生物法測定以下抗生素:
阿米卡霉素Amikacin，卷曲霉素Capreomycin，氯霉素Chloramphenicol，金霉素Chlortetracycline，環絲氨酸Cycloserine，地美環素Demeclocycline，二雙氫鏈霉素Dihydrostreptomycin，多西環素Doxycycline，短桿菌肽Gramicidin，卡那霉素Kanamycin，甲烯土霉素Methacycline，土霉素Oxytetracycline，吡咯烷甲基四環素Rolitetracycline，鏈霉素Streptomycin，四環素Tetracycline，托普霉素Tobramycin，醋竹桃霉素Troleandomycin
抗生素測定培養基3號配方與配制方法
| 成分 | g / L |
| 蛋白胨 | 5 |
| 酵母提取物 | 1.5 |
| 牛肉浸粉 | 1.5 |
| 葡萄糖 | 1 |
| 氯化鈉 | 3.5 |
| 磷酸氫二鉀 | 3.68 |
| 磷酸二氫鉀 | 1.32 |
| pH 7.0±0.05 |
配制方法：
1. 稱取17.5g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。
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.
實驗結果
ATCC標準菌株 測定抗生素 溫度與時間 大腸埃希氏菌ATCC10536 Chloramphenicol 32-35°C/24 h 肺炎克雷伯菌 ATCC10031 Capreomycin 36-37.5°C/16-24 h Dihydrostreptomycin Streptomycin Troleandomycin 金黃色葡萄球菌ATCC29737 Amikacin 32-35°C/24 h Chlortetracycline Cycloserine Demeclocycline Doxycycline Kanamycin Lincomycin Methacycline Oxytetracycline Rolitetracycline Tetracyclin Tobramycin 希氏腸球菌ATCC10541 Gramicidin 36-37.5°C/16-18 h 金黃色葡萄球菌ATCC9144 Tylosin 35-39°C/16-18 h