| Abstract: | A low-angle light-scattering instrument has been used to measure molecular weights of native calf-thymus and T7 DNA. Molecular weights obtained by extrapolation of angular data to 0° from measurements above 30° are less than molecular weights from extrapolation of data taken at low angles (below 30°). The low-angle molecular weights determined for calf-thymus DNA and for T7 DNA agree well with estimates of weight-average molecular weight obtained with other techniques. The low-angle light-scattering molecular weight for calf-thymus DNA is higher than previously reported values by light scattering at angles above 30°. A concentration dependence in the scattering from DNA solutions is also observed. |
