The sample volume required depends on the cuvette used to measure DLS, but can be performed with samples sizes ranging from 40 to 3000 μL. However, negatively charged carboxylate polystyrene microspheres particles readily gave accurate viscosity measurements over a range of temperatures (0–100 ☌). The styrene particles, frequently used as particle size standards, gave unsatisfactory results for our DNA samples as did C-6 derivatized silica and positively charged amino polystyrene microspheres. Viscosity measurements for water and aqueous solutions of calf thymus DNA made using DLS were compared with those from a U-tube viscometer. We inverted the usual protocol and endeavoured to determine viscosity for samples of known particle size. Most applications of DLS involve determining particle size for samples of known viscosity. We report the development of a new method for measuring dynamic viscosity by measuring dynamic light scattering ( DLS) data for a range of particles of well-defined size. It is, however, difficult to measure precisely, reproducibly and accurately for aqueous solutions on a micro-litre volume scale, which is what is usually needed for biological samples. Viscosity is a key parameter for characterising the behaviour of liquids and their flow.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |