The knowledge of molecular biology is becoming integral to keep pace with the newer diagnostic techniques, advances in understanding the pathogenesis of diseases and even day-to-day patient management. Genetic tests can be classified according to their purpose as diagnostic testing, carrier testing, prenatal testing and presymptomatic testing. The most obvious is diagnostic testing in which a DNA-based test is used to confirm or rule out a specific genetic disorder. A prerequisite for diagnostic testing is the prior knowledge of mutation spectrum in the particular population. Once the mutations in the family are known, carrier testing and prenatal diagnosis can be offered to at-risk persons. In presymptomatic genetic testing, a ealthy person is tested for a condition with delayed onset.This manual is a compilation of molecular diagnostic techniques available in the literature for common single gene disorders. This manual is a compilation of molecular diagnostic techniques available in the literature for common single gene disorders and is currently in use in our laboratory. Summary of relevant information has been provided about the disease before giving details of the actual laboratory procedures This book is a compilation of molecular techniques that are routinely performed for diagnosis of common single gene disorders.It provides a brief summary about the disease, etiology and inheritance with illustrations before giving the details of the actual laboratory procedures.This is an easy-to-follow manual and will be very useful and handy for the aspiring diagnostic laboratories, young scientists and clinical geneticists