Book excerpt: Detection of minimal residual disease (MRD) is increasingly used in the management of leukemia patients. A wide variety of methods have been developed and include technologies designed to detect residual malignant cells beyond the sensitivity of conventional approaches such as morphology and banding cytogenetics in leukemia. The choice of the best method depends on the biology of the individual malignancy, i.e. on the determination of specific markers which are useful to differentiate between leukemic cells and normal hematopoiesis in leukemic patients. These markers include leukocyte differentiation antigens, fusion transcripts, transcripts overexpressed by mutated or nonmutated genes, rearranged genes, and individual markers like polymorphic repetitive DNA sequences. The major technologies for MRD detection, their advantages and disadvantages and their clinical applications are discussed in this special issue - from 'bench to bedside'. Providing a comprehensive overview on the significance of MRD in the evaluation, treatment and follow-up of hematologic malignancies, it will be of great value to hematologists, researchers interested in leukemias and lymphomas as well as laboratory technicians.