The theoretical background of cytogenetics as well as the practical methods to investigate chromosomes from Drosophila to mammals and humans are presented in this book. Theory and practical protocols on the following topics are included: Cell culture methods, chromosome preparation and banding techniques, radioactive and fluorescent in situ hybridisation (FISH) methods and their derivates (chromosome painting), meiotic chromosome methods using light and electronic microscopy, the polytenic (Drosophila) and lampbrush (urodeles) chromosomes as well as flow and slit scan cytometry. The editors, all at INRA, played a prominent part in the development of cytogenetics. Paul Popescu, a specialist for domestic animals worked with gene mapping, Helene Hayes, together with Popescu showed the homology of bovine and human chromosome disorders, and Bernard Dutrilaux focused on human cytogenetics.