This volume was originally intended to be an English translation of the book MetllOden in der medizinischen Cytogenetik, published in 1970. Just about then, however, a number of new techniques were introduced in human cytogenetics and soon acquired the utmost importance, parti­ cularly in clinical diagnosis, so that the English edition had to be con­ siderably enlarged. As a result, there are now twelve chapters instead of eight, and two additional authors have been called upon, Dr. KRONE and Dr. SCHNEDL. In addition to the up-to-date presentation of con­ ventional methods of cell culture and techniques for the preparation and identification of human chromosomes, this text covers the various tech­ niques of producing banding patterns and applying them in chromo­ some identification. Further, it deals with the culture of amniotic fluid cells and gives instructions for handling tissue-culture cells for bio­ chemical analysis; it thus meets the ever-increasing requirements of a modern cell-culture laboratory. To paraphrase the aims of this book, we quote part of the preface to the German edition: "It was intended to collect the various methods so as to make them accessible for laboratory use. Furthermore, it is hoped that the reader faced with current research problems will be stimulated to modify and supplement the techniques described, instead of merely applying them automatically. In a rapidly developing field, some methods are still preliminary, and no final presentation seems possible.