The practical study is a supplement to the theoretical classroom knowledge. It helps to understand the subject more precisely. The present book entitles "comprehensive laboratory Manual in Biology" Meant for class XII under 10 + 2 pattern of Central Board of Secondary Education. The subject matter of the book has been written in accordance with the latest syllabi prescribed by the CBSE and other boars of Secondary Education. The book has been designed as a reference rather than copy down the instruments. This book has its own identity because of the following features: 1. The subject matter has been written in a simple and lucid language. 2. A brief information about theoretical aspect of the experiments has been given in the beginning of each experiment. 3. Each experiment has been fairly illustrated with all possible details. 4. A number of viva voce questions have been given at the end of each experiments.