Book excerpt: Photochemistry of Proteins and Nucleic Acids focuses on the effects of ultraviolet and visible radiations on proteins and nucleic acids. The book first discusses some principles of photochemistry, including the laws of photochemistry and factors influencing photochemical reactions in solutions. The text describes absorption and luminescence spectra of nucleoproteins and their components, including principal absorbing groups in proteins, nucleic acids, and nucleoproteins. The selection also highlights the action of ultraviolet light on proteins; photochemical and photosensitized inactivation of enzymes; and the photochemistry of purine and pyrimidine derivatives. The text also discusses nucleic acids and oligo- and polynucleotides. Topics include photochemical degradation of nucleic acid; kinetics of biological inactivation of nucleic acids; nucleoproteins; and reversibility of nucleic acid photolysis. The book also encompasses the inactivation of viruses, including inactivation studies with a plant virus, bacteriophages, and photochemically produced vaccines. The text also presents some problems in photobiology and some techniques in photochemistry. The text is a good source of information for readers interested in the study of proteins and nucleic acids.Based on the standards and codes from Fo