The aim of this book is to provide detailed information of methods used for analysis of antioxidant, antimicrobial and phytochemical compounds present in plants. Plant based medicines are used in all civilizations and cultures, and have been one of the indispensable means of defence in maintaining health and combating diseases worldwide. With the increasing demand of plant based medicines for use in pharmaceuticals and dietary supplements, biotechnology has emerged as a powerful tool for their conservation and improvement. This book discusses all major assays for evaluation of important constituents naturally present in plants and will serve as a useful tool for research workers and students in a variety of disciplines, including biotechnology, microbiology, food science, nutrition, chemistry, and biochemistry as well as for health professionals. Researchers in the industry, universities and research laboratories will find it very useful and informative as it provides detailed methodology of methods that can be used in this ever-growing area.