Development and application of advanced electron microscopy techniques for materials in biological systems

Sammanfattning: Theoretically, electron microscopy and scanning probe microscopy offer information on a scale beyond the optical microscope. However, the quality of the micrograph and the obtained information is limited by the sample preparation. Each sample has its own characteristics that need special precautions, meaning that sample preparation is a continuously developing science. In this thesis several microscopy techniques are further developed and refined, and the problems involved are discussed both in general terms and more specifically for: Immunogold labelling of budded baculovirus, was performed to support the expression of a test protein, in a new display system for screening of proteins. Immunogold labelling was performed to locate hormone-sensitive lipase (HSL) within the beta cells in the islets of Langerhans. HSL was shown be located to the insulin storing granules. TEM was used to investigate the nature of the first precipitate formed in a solution designed to mimic the inorganic composition of the blood plasma of dialysis patients, i.e. with increased phosphate concentration. TEM and SEM were used to analyze the effects of modifying α-TCP, to be used as bone support material, by increasing milling time of the α-TCP particles or by substitution with silicon or strontium. SEM was used to put further light on release mechanisms for polymer coated pellets to be used in multiple-unit pharmaceutical devices. The possibility of correlative imaging by AFM, TEM and SEM of the exact same sample object was investigated on stained and unstained baculovirus. For further development of general microscopy protocols, different grid designs were investigated by SEM and commonly used treatment protocols, for modifying the hydrophilic properties of supports, were ranked by measuring the water contact angle on carbon after treatment. For cryo-TEM, the effect of adding a surface active stain to a virus-suspension on the frequency of virus particles in the vitrified film was evaluated by surface tension measurements.