COMBINATION OF MODERN VISUALIZATION TECHNIQUES FOR IMAGING OF BIOLOGICAL SAMPLES

We have used several visualization techniques to characterize biological objects. A micro-radiography with the hybrid single photon counting silicon pixel detector Medipix2 (matrix 256 x 256 sq. pixels of 55 mu m pitch) is an imaging technique using Xrays in the studies of internal structures of objects. The detector Medipix2 is used as an imager of an ionizing radiation, emitted by X-ray tubes (micro or nano-focus FeinFocus). An unlimited dynamic range of the Medipix2 detector and a high spatial resolution below 1 mu m is particularly suitable for a non-destructive and non-invasive radiographic imaging of small biological samples in a living state, including in vivo observations and a micro-tomography. Contrast agents (based on iodine or lanthanum) could be used for dynamic studies inside of organisms. Infrared digital photography has ability to shot still photographs or movies in complete dark. Is it also possible to use it for studies of internal organs and structures inside of living biological objects. Field emission scanning electron microscopy (FESEM) in low temperature mode is sophisticated recent technique successfully used in biological laboratories. The main advantage is ability to study details of tissues and cells close to living state at very high magnification. Special cryo-transfer system connected to FESEM allows deeply frozen samples to be prepared in way like freeze-fracturing followed by freeze-etching for observation directly inside of electron microscope. Combination of information from all above mentioned techniques could give us very powerful visualization tool for complex studies of biological specimen.