Abstract: A process for rapidly enumerating viable biological entities is disclosed, wherein viability is determined by the critierion of growth of biological entities contained in microdroplets. Alternatively, in some cases, viability is determined by use of vital staining of biological entities contained in microdroplets. The process involves formation of microdroplets, which are very small volume liquid or gel particles, such that some of the microdroplets contain biololgical entities, followed by measurements of biological entities and of microdroplet volumes, such that use of statistical analysis can be used self-consistently to determine the number of viable entities per volume of a sample.