This book provides comprehensive descriptions of the innovative strategies and methodologies for detecting miRNA expression, their application in miRNA research and their potential as tools for clinical diagnosis and prognosis. It begins with the introduction of the overall concept and strategies of miRNA expression detection methods emphasizing the need of a wide variety of these methods to suit specific requirements for research and clinical examination in laboratories. Schematic diagrams are included where needed and appropriate for better illustrating the principle of the methodologies. In addition, flowcharts are also provided to outline the protocols for each of the miRNA expression detection methods. This book is aimed to target both researchers involved in miRNA research of any fields in universities and research institutions and medical practitioners who are interested in developing or utilizing miRNA profiling as a complementary and an alternative strategy for clinical diagnosis of human disease.