ANALYSIS OF SLIT-SMEARED SMALL-ANGLE SCATTERING DATA FROM INTERACTING SYSTEMS VIA INDIRECT-TRANSFORMATION METHODS

摘要

The indirect-transformation method in reciprocal space (ITR) is used to obtain the desmeared small-angle X-ray scattering (SAXS) curve of semidilute aqueous solutions of fragmented DNA, which have interparticle interference effects. Systematic errors are observed only for a particular concentration, at very low values of the scattering vector q of the calculated desmeared intensity J(desm). Although interparticle interactions already exist for the less concentrated solution (10 g l(-1)), the interference effects fall below the measured q range. In order to know if these effects are in fact negligible on the corresponding SAXS curve, the cross-section distance-distribution function p(c)(r) is calculated using the indirect-transformation program (ITP) and both the ITR program and ITP are tested to calculate J(desm). It is concluded that for the less concentrated solution ITP gives the best solution, allowing determination of the particle form factor. For the higher concentrations, the use of ITR desmearing allows one to obtain the interference function. [References: 17]