Improving image quality of Rhodnius prolixus head using different types of staining methods and synchrotron radiation phase contrast microtomography

Microtomography has already shown to be a powerful tool for studying insects' morphology yielding images with high resolution, in a non-destructive way and with fast data acquisition. Biological samples such as insects usually require the use of X-ray absorbing contrast agents in sample preparation, as there is a very little difference in the attenuation coefficient among soft tissue types. We have shown in previous studies that Synchrotron Radiation Phase Contrast Microtomography can produce high-quality images of Rhodnius prolixus head, however, there are some structures that cannot be visualized yet. Here, we used different combinations of fixatives and staining and the results were compared using two image quality parameters (contrast and signal-to-noise ratio). The combinations tested here were Bouin's Fluid + Osmium tetroxide, Bouin's Fluid + Iodine, Glutaraldehyde + Osmium tetroxide, Glutaraldehyde + Phosphotungstic acid. Glutaraldehyde. Our data revealed significant differences between the different combinations of fixative/staining.