Technical advances in cytogenetics have taken place in phases. Various staining techniques have emerged, resulting in a more vivid picture of human chromosomes. Several books were published recently on such technical improvements. A recent addition is the technique called FISH (fluorescence in situ hybridization). The application of the FISH technique is summarized in the Atlas of Whole Chromosome Paint Probes: Normal Patterns and Utility for Abnormal Cases, by Jalal, Law, and Dewald. However, this book serves an additional purpose. It starts with a brief introduction followed by materials and methods, with emphasis on sequential GTL (G-bands by trypsin using Leishman) and the FISH technique. The primary objective of this atlas is to illustrate the normal fluorescence patterns and cross-hybridization reactions of different probes to chromosomes in green and orange spectra. This information is highly valuable due to the common occurrence of nonspecific binding sites in chromosomes. The authors have used whole-chromosome paint (WCP) probes by Vysis™ which are designed ''. . . for research and investigational use only and are not used in diagnostic procedures . . .'' owing to pending approval by health agencies for their clinical applications. Also, the authors have included a separate section on ''representative abnormal cases'' from samples such as amniotic fluid, peripheral blood, bone marrow, and products of conception. This is an excellent atlas depicting chromosome painting, and will serve as a superior reference source in clinical cytogenetics laboratories that are engaged in FISH studies.