Lab to find lactobacillus. After placing 1-2 drops of yogurt on Lactobacillus MRS Agar plates. Incubating in an anaerobic systems for 72 hours ( per lab manager suggestion versus the 24-48 hours) at 32C we will do the final step for the lactobacillus lab. Let’s hope there is growth on the plates. Students take 2 identical colonies from these plates create a 2 McFarland turbidity* with the API CHL medium. The honeycomb wells on the tray of the API 50 are filled with deionized water. The homogenized sample is pipetted into each of the API strip tubes. To create an anaerobic environment the sample must not go over the tube into the cupules. The tubes are overlaid with mineral oil. Anaerobic incubation for 48 hours at 30-37 C is next. Then observe which types of carbohydrates were fermented. The attached article compares API 50 CH and RAPD in determining lactobacilli species. api50 in use