This textbook has been designed to meet the needs of B.Sc. Third Semester students of Zoology as per Common Minimum Syllabus prescribed for all Uttar Pradesh State Universities and Colleges under the recommended National Education Policy 2020. It comprehensively covers two papers, namely, theory paper on Molecular Biology, Bioinstrumentation and Biotechniques and practical paper on Bioinstrumentation and Molecular Biology Lab. The Molecular Biology part of the book emphasizes the fundamental features of various aspects of DNA, RNA, and protein structure, function, and expression. The regulation of Gene expression in Prokaryotes and Eukaryotes is presented in a very lucid and comprehensive way.