Molecular diagnostics has become a growing part of the clinical laboratory. It includes all tests and methods to identify a disease and understand the predisposition for a disease analyzing DNA or RNA of an organism. Rapid advances in molecular diagnostics enables basic research and results in practical diagnostic tests. The molecular diagnostic marketplace offers a growth opportunity given the interest in utilizing molecular tools to precisely target therapeutics. Molecular diagnostics and biosensors are widely used in medicine, agriculture, industry, and research, as well as environmental, military, and criminal investigations. This book compiles state of the art research and developments on the use of nucleic acids in molecular diagnostic testing will be described. Real world examples will be discussed to illustrate technical capabilities as well as the medical relevance of such testing.