产品名称:结晶紫中性红胆盐琼脂;VRBA培养基;VRB琼脂
英文名称:Violet Red Bile Agar;VRBA;VRB Agar
培养基类型:选择性培养基
级别:for microbiology
产品规格:250g、500g
产品外观:麦秸色至粉色均一粉末。
颜色与澄清度:紫色凝胶。
保存条件:密封,2-25°C保存。
注意事项:本产中含有刺激性成分。避免摄入、呼入和皮肤接触。
配制方法:称取本品51.5g于1L蒸馏水或去离子水
中(可按比例增加或减少配置量),搅拌煮沸
溶解1分钟,冷却至50-55℃倾注平板。
Formula(配方): g/L
Peptone(蛋白胨) 7.0g
Dextrose (葡萄糖) 10.0g
Lactose (乳糖) 10.0g
Yeast Extract(酵母浸粉) 3.0g
Sodium Chloride(氯化钠) 5.0g
Bile Salts No.3(3号胆盐) 1.5g
Neutral Red (中性红) 0.03g
Crystal Violet(结晶紫) 0.002g
Agar(琼脂) 15.0g
pH7.4±0.2 (25℃)
实验方法:
Spread Plate Method:
1. Prepare decimal dilutions in sterile diluent to obtain 30-300 CFU per plate.
2. Aseptically inoculate agar surface with 0.1ml of well mixed diluted sample.
3. Spread the dilution evenly over the surface of the medium.
4. Using a sterile spreader device, distribute the inoculum evenly over the agar surface.
5. Incubate plates aerobically for 48 +/- 2.0 hours at 35oC.
Pour Plate Method:
1. Melt agar by placing in a boiling waterbath until liquified.
2. Cool media to 45-50oC. Maintain in a 45-50o waterbath until ready to pour.
3. Prepare decimal dilutions in sterile diluent to obtain 30-300 CFU per plate.
4. Place a 1ml inoculation into a sterile petri plate.
5. Aseptically pour approximately 18ml of the cooled media (45-50oC.) over the inoculum. Carefully swirl the plate to mix the inoculum evenly.
Note: After autoclaving, do not heat media longer than 3 hours at 45-50oC. Sterile solidified medium can only be remelted once.
6. Allow to solidify.
7. Incubate plates aerobically for 48 +/- 2.0 hours at 35oC.
结果与分析:
乳糖发酵型微生物,包括大肠菌群,产生粉色至红色菌落,一般在菌落四周有一圈红色的胆盐沉降带。
在表面生长的E.coli菌落边缘完整,在培养基内部生长的菌落则呈凸镜状。
某些肠球菌也可能生长,产生针尖大小的枚红色菌落。
非乳糖发酵型微生物形成无色菌落。