High pressure freezer. (360G-Wellcome-085952_Z_08_Z)

High pressure freezing (HPF) is the gold standard method for high fidelity fixation of biological material for electron microscopy. We have already acquired more than half of the funds required for this equipment and we request the residual support required this application. HPF an extremely rapid, method for the immobilization and fixation cells and tissues and is particularly well suited for ultrastructural examination of microbial cells and human tissues that are difficult to fix by conventi onal non-cryo-methods. Samples thus prepared are also ideal for ultrastructural studies of tissue composition by immunolocalisation. Recently launched HPF equipment achieves a much larger depth of freezing and offers attachments that allow correlative microscopy, whereby structures identified by fluorescence labelling are subsequently examined (after HPF) in the electron microscope. It is well known that fungal cells and human skeletal tissues that we work with are notoriously difficult to pr epare for ultrastructural analysis. They are poorly preserved by conventional fixation protocols and specimens are prone to shrinkage, and the loss and rearrangement of labile components. The two major research programmes leading this application have extensive requirements for high quality imaging. The equipment would also be used by an extended group of Wellcome funded staff at Aberdeen.