| 產品名稱： | TOS丙酸鹽瓊脂；BSC丙酸鹽瓊脂；雙歧桿菌選擇計數瓊脂基礎；TOS-MUP瓊脂基礎；轉糖基半乳糖苷低菌糖瓊脂；TOS培養基 |
|---|---|
| 英文名稱: | BSC Propionate Agar；TOS-propionate agar medium acc. ISO ；Bifidobacteria Selective Count Agar Base；TOS-MUP Agar Base；Transgalctosylated oligiosaccharide agar medium |
| 培養基類型: | 選擇性培養基 |
| 級別: | for microbiology |
| 品牌： | ELITE-MEDIA（艾禮培養基） |
| 產品目錄號: | M1008-01、M1008-02 |
| 產品規格: | 250g、500g |
| 保存條件: | 室溫（8-25℃），避免陽光直射 |
| 產品外觀: | 淡黃色至淡棕色均一粉末 |
| 顏色與澄清度: | 淡黃色凝膠，半透明 |
| 注意事項: | 避免攝入、呼入、皮膚接觸 |
| 相關產品: |
雙歧桿菌選擇性添加劑A 雙歧桿菌選擇性添加劑B |
產品描述：
TOS丙酸鹽瓊脂培養基（TOS-propionate agar medium）也稱雙歧桿菌選擇計數瓊脂基礎（Bifidobacteria Selective Count Agar Base）、BSC丙酸鹽瓊脂（BSC Propionate Agar）、TOS-MUP瓊脂（TOS-MUP Agar）、轉糖基半乳糖苷低菌糖瓊脂（Transgalctosylated oligiosaccharide agar medium），被推薦用于菌落計數法計數奶制品中總雙歧桿菌數。原理：
莫匹羅星鋰是一種抑菌劑，能夠抑制乳桿菌、乳球菌、鏈球菌和明串珠菌。加入乙酸后可使培養基pH降低，增加選擇性。培養基配方
| 組分 | g/L |
| 酪蛋白水解物 | 10 |
| 酵母提取物 | 1 |
| 磷酸二氫鉀 | 3 |
| 磷酸氫二鉀 | 4.8 |
| 硫酸銨 | 3 |
| 硫酸鎂，七水 | 0.2 |
| L-半胱氨酸鹽酸鹽，一水 | 0.5 |
| 丙酸鈉 | 15 |
| 低聚半乳糖 | 10 |
| 瓊脂 | 15 |
| pH值 | 6.3 +/- 0.2 |
雙歧桿菌選擇性添加劑A
| 組分 | 每瓶含量 |
| 莫匹羅星 | 25mg |
| 無菌蒸餾水 | 5mL |
雙歧桿菌選擇性添加劑B
| 組分 | 每瓶含量 |
| 冰乙酸 (1%) | 5ml |
配制方法：
用1000ml蒸餾水重懸62.02g脫水培養基，加熱煮沸至完全溶解。115°C 高溫蒸汽滅菌15 min。待培養基冷卻至50°C左右時加入2瓶莫匹羅星鋰添加劑（雙歧桿菌選擇性添加劑A），混勻后倒平板。為進一步提高培養基的選擇性，可以加入2瓶乙酸添加劑（雙歧桿菌選擇性添加劑B）。
注意：
該培養基對熱敏感，過度加熱會顯著影響培養基的功能。
實驗方法：
Test Procedure:Dried milk products (e.g. infant formula):
Mix the content of a closed sample pack if possible or use a sterile spatula to get a homogenous sample. Weigh 90g of diluent (Quarter-strength Ringer solution) in each of the 250 ml pre-sterilized bottles. Add 10g of the test sample into the bottle with the diluent at 45°C. To dissolve the test sample, swirl slowly. Place in the water bath (45°C) while shaking occasionally. Cool down under running tape water for 2 minutes. Keep all suspension for 30 minutes in the fridge and start directly with the examination.
Yoghurt and yoghurt-like products:
Mix the content of a closed sample pack if possible or use a sterile spatula to get a homogenous sample. Weigh 90g of diluent (Quarter-strength Ringer solution) in each of the 250 ml pre-sterilized bottles. Add 10g of the test sample into the bottle with the diluent at 45°C. To dissolve the test sample, shake and start with the examination as fast as possiplbe
Examination:
Do 1:10 dilution steps with dilution solution until the a concentration of 200-500 cfu/ml is obtained. Transfer 1 ml of the appropiate dilutions into a petri dish and add 12-15 ml medium (in duplicates). Mix gently and let solidify. The time between ending the preparation of the primary dilution until addition of culture medium shall not exceed 15 min.
Imediately after solidification of the medium, invert all Petri dishes in the anaerobic culture jar or anaerobic incubator at 37°C for 72 hrs ± 3 hrs. Count the colonies after incubation. Bifidobacterial colonies are recognized by their whitish colour and acetic acid odour. Some of the bifidobacterial strains may appear in different colony size as well as colony appearance on the same plate (1). Select typical colonies for microscopic examination.
Optional a F6PPK-assay can be performed to confirm the result.