Flow cytometric analysis of molecular, biochemical, genetic and developmental parameters using cellular fluorescence techniques as well as fluorescence-activated (FACS) or magnetic (MACS) cell sorting technologies provide unique options for molecular and cellular biology. In recent years, these technologies have been considerably advanced. In this second edition, all chapters have been updated according to the recent improvements and modifications. Further, new protocols have been added, such as on magnetic selection, magnetofluorescent liposomes, the cytometry of secreted products and microbead assays, as well as reporter gene assays for cytometry and cell selection. The recent technical developments allow diagnostic differentiation of cells according to specific gene expression, identification of rare disease-associated cells and isolation of well-defined cells at high purity for cell therapies.