This book aims to present, in a concise manner, the technologies used for DNA, gene expression, and protein research. Recently developed high-throughput techniques — such as single nucleotide polymorphism genotyping, fluorescent in situ hybridization, microarray-based expression profiling, quantitative polymerase chain reaction, and MALDI-TOF-based methods — are widely used in many areas of biomedical research today. The book gives an overview of the rationale on which these methods are based, as well as their advantages and disadvantages. It is not meant to include detailed laboratory protocols; rather, the emphasis is on understanding the principles to aid decision making in a period when there is a wide and sometimes bewildering choice of approaches and equipment. Future technical developments and clinical applications are also discussed.