A systematic investigation of key factors of nucleic acid precipitation toward optimized DNA/RNA isolation

Nucleic acid precipitation is important for virtually all molecular biology investigations. However, despite its crucial role, a systematic study of the influence factors of nucleic acid precipitation has not been reported. In the present work, via rational experimental design, key factors of nucleic acid precipitation, including the type of nucleic acid, temperature and time of incubation, speed and time of centrifugation, volume ratio of ethanol/isopropanol to nucleic acid solution, type of cation-containing salt solution and type of coprecipitator, were comprehensively evaluated in an attempt to maximize the efficiency of nucleic acid precipitation. Our results indicate that the optimal conditions of each influence factor of nucleic acid precipitation may vary in accordance with the chemistry, structure and length of nucleic acids. METHOD SUMMARY To maximize the efficiency of nucleic acid precipitation, the key factors, including incubation and centrifugation conditions, and the volume ratio of polar solvents, cation-containing salts and coprecipitators, were systematically evaluated. To gain more practical information, four types of commonly used nucleic acids were tested. The results indicate that the optimal conditions vary greatly in accordance with the type of nucleic acids under study.