The knowledge of the quantification processes for metabolic active cells of different microorganisms in cultivations continues to advance in different area. To a large extent, the methodology presented here on a same platform can be used in both lab and industrial scale and also advanced with other different microorganisms. The primary aim of this book is to bring together many of the current experimental methods on quantification of metabolic active cells underlying recent progress in a range of areas within microbiology and biotechnology. The methodologies described here can be useful for teaching purpose and also for the practical course for students in Colleges and Universities to assist both teacher and student. Simple protocol and figures are provided in chapters to understand the problem.