During 1950–1962, nucleic acids became recognized as the blueprint of heredity and structural molecules whose chemistry could be interrogated by new methods. Researchers refined purification techniques for deoxyribonucleic acid, probed base composition, and used enzymatic and chemical treatments to reveal RNA structure and cyclic nucleotide products. A unifying methodological trend emerged, combining purification, physical separation, and chemical biology to establish the experimental foundations of molecular genetics. Historical Significance: These findings cemented deoxyribonucleic acid as the genetic material, reshaping the fundamental understanding of heredity. The development of reliable DNA isolation methods and buoyant-density analysis established quantitative frameworks for characterizing nucleic acids and their interactions with proteins, enabling subsequent advances in sequencing and genome analysis. Together with RNA structural studies, these works anchored a molecular view of heredity and laid the groundwork for the modern era of molecular genetics.