Determination of nucleic acids in acidic medium by enhanced light scattering of large particles

The large particle light scattering technique was first developed as a sens itive and convenient analysis method for microdetermination of nucleic acid s by using a common spectrofluorometer. In 0.1 mol l(-1) HCl, H2SO4, or HNO 3 solution, the nucleic acids can aggregate to form large particles whose d imensions are comparable to the wavelength of UV-Vis light. The large parti cles can result in very strong light scattering which is well proportional to the concentration of nucleic acids in the range of 0.06-100.0 mu g ml(-1 ) for calf thymus DNA, 0.05-60.0 mu g ml(-1) for fish sperm DNA, and 0.6-90 .0 mu g ml(-1) for yeast RNA. The detection Limits (3 sigma) are 18.0 ng ml (-1) for calf thymus DNA, 16.0 ng ml(-1) for fish sperm DNA, and 57.6 ng ml (-1) for yeast RNA, respectively. Six synthetic samples were determined wit h satisfactory results. (C) 2000 Elsevier Science B.V. All rights reserved.