Otimização de um protocolo de fixação e marcação para estudo do Rhodnius prolixus usando microtomografia síncrotron

Abstract

During the years microtomography using synchrotron light technique has proved to be an excellent tool to study the internal and external structures of Rhodnius prolixus, main insect vector of Tripanossoma cruzi, and the etiologic agent of Chagas Disease. However, the first works have shown that the visualization of some structures can vary according to the type of beam and sample treatment. The objective of this work is to develop a protocol to identify the best fixation and staining sample treatment by the evaluation of the image quality parameters, allowing the segmentation of different structures of Rhodnius prolixus in two different periods of 5th instar (unfed and ecdysis). The samples were tested with different combinations of fixatives and staining. The choice of the best protocol was done with qualitative analyses (through the observation of the images) and quantitative analyses (through the calculation of image quality parameters, such as contrast and signal-to-noise ratio). The measurements were performed at the Brazilian Synchrotron Light Source (LNLS), Campinas-Brazil, and at ELETTRA Synchrotron Facility, Trieste-Italy.