This advanced level textbook provides a comprehensive overview of recent developments in the area of molecular based diagnostics (including nucleic acids, biosensors and immunoessays) of disease markers. It also covers the impact of techniques such as in vitro nucleic acid amplifications (e.g. PCR) and other amplification methods, as well as gene and biochip production and automated techniques such as fluorescent sequencing.The book discusses key concepts where new and merging areas, including pharmacogenomics, proteomics and functional genomics, are being researched and developed. In addition, examples are given where this new area of bioscience has or may be successfully applied.