In the recent past most of the author published related but different work to this. In the light of the changes the author has enlarge the text. Some articles have been incorporated.The text in this still remains logical and teachable.Each topic covered in this more or less self sufficient in it self. Whereas necessary modern spectroscopic method used e.g.mass spectrometry, NMR spectroscopy etc.This book will further help the students and also useful for B.Sc., M.Sc., Micro Biology, BioTechnology ,Pharmacy and related fields. Lata Potey.