High Pressure Freezing Machine
The HPM010 allows cryo-fixation and vitrification of specimens up to 200 µm in depth. In the EMCF we are routinely freezing bacterial and yeast cells, cultured mammalian cells, Drosophila embryos, nematodes, zebrafish embryos, marine organisms and several types of tissues. Adherent cells are typically grown on sapphire discs that can be used directly in the HPF machine. Other specimens are placed inside metal planchettes (with a depth between 40μm – 200μm), which are 3 mm in diameter and have a central cavity of 2 mm. To achieve vitrification, a cryoprotectant or filler is often added to the sample just before freezing. A second carrier with a flat surface is placed on top to protect the specimen. This sandwich is inserted into the machine and the specimen is exposed to 2000 bar of pressure within milliseconds while almost simultaneously being cooled down to liquid nitrogen temperature (-196oC).
