The primary objective of this book is to illustrate recent concepts in molecular biology with focus on the application to human, animal and plant pathology, in numerous aspects like analysis, prevention and treatment of diseases, prognosis, etiology and use of these methodologies in comprehending the pathophysiology of several diseases that impact living beings. The topics included are measuring DNA damage; overview of PCR principles; submicroscopic human parasitic infection and real time PCR techniques in cancer investigations. This book will be beneficial for researchers, students and professionals engaged in the field.