Vitroids™ and LENTICULE^® discs contain viable microorganisms in a certified quantity (ISO 17025), produced under reproducible conditions (ISO Guide 34) with strains obtained from CECT^®, NCTC and other collections. The discs consist of bacteria or fungi in a solid water soluble matrix. Microorganisms in this form are stable for at least one year and are in a viable stage (no lag phase or recovery time)