High pressure microscopy--a powerful tool for monitoring cells and macromolecules under high hydrostatic pressure.

A high pressure chamber, which withstands a pressure up to 300 MPa has been developed. The so-called HPDS (Hartmann, Pfeifer, Dornheim, Sommer) High Pressure Cell in combination with an inverted microscope and an analysis system allows brilliant microscopic colour pictures with an optical resolution better than 0.56 microm. The pressure chamber allows the in situ observation of dynamic changes of microscopic structures in bright field, phase contrast and fluorescence microscopy. This publication should demonstrate the capabilities of the system using results of experiments with two types of Spirogyra algae. The pictures have shown significant variations of the chloroplasma and the cell wall membrane at pressures of up to 120 MPa. The new system provides a simple way to perform microscopic analyses at pressures of up to 300 MPa.