Used for preparing the inoculum of Lactobacillus leichmannii ATCC 7830 in the microbiological assay of Vitamin B12. Recommended by USP. For preparing inoculum, the culture is grown in 5 ml sterile B12 Inoculum Broth for 18 to 24 hours at 35°C and then the culture is centrifuged to obtain cell sediment. The supernatant is decanted and the cells are suspended in B12 Assay Medium (M036).This cell suspension is used as an inoculum after adjusting its density.