Low-angle x-ray scattering from lyophilized blood constituents

The characteristic nature of low-angle x-ray scattering from biological samples and its dependence on molecular structure is a subject of increasing interest. In this work, low-angle x-ray scattering from lyophilized (freeze-dried) whole blood, haemoglobin (Hb), serum and red blood cell membranes is studied. The scattering profiles of these samples are found to be reproducible and characteristic. A number of characterization parameters are introduced, showing significant differences between the investigated samples. The sensitivity of the scattering profiles of whole blood, Hb and serum towards induced molecular level variations is examined after doses of gamma irradiation of 3, 6 and 9 Gy. The full width at half maximum (FWHM) of the second peak of scattering and the percentage ratio of amplitudes of the first and second peaks (I1/I2)% are found to be the parameters most sensitive to irradiation. For all irradiated samples, it is observed that the FWHM of the second peak is always greater than the control, while the ratio (I1/I2)% is always smaller than the control.