FIGURE 1.

The piston cylinder device (http://www.depthsoftheearth.com) and protocol used for carrying out the high pressure experiments. (A) The Teflon^® capsule is filled with cell suspension and is capped by a Teflon^® lid for the experiment. The dome of liquid indicates the capsule is completely filled and contains no air. (B) The capsule is placed inside a pre-formed cylinder (sleeve) made from pressed powdered NaCl that acts as a pressure-transmitting medium with NaCl plugs capping both ends. (C) The sample assembly is then placed inside the central bore of the pressure plate. The tungsten carbide piston is inserted from the top. Thermocouple wires inserted from the bottom and passing through the lower pressure support block to make contact with the sample capsule were used to measure the temperature. (D) Pressure is applied by hand pumping the oil-driven hydraulic ram to raise the pressure plate containing the sample assembly and force it against the piston that is driven down to reduce the sample volume. The pressure is transmitted to the sample through slight deformation of the walls of the Teflon^® container that maintains its shape and remains intact during the experiment and subsequent recovery.