Abstract: The present invention provides composite biological devices that include biological material as an integral component thereof. The devices can be used for measuring metals, for example, particularly toxic metals such as mercury.

Abstract: A system for preparing specimens in a controlled environment to insure that a liquid or partially liquid specimen is maintained in its original state while it is being prepared, and once prepared the specimen is vitrified or solidified with minimal alteration of its microstructure. The controlled environment is provided within a chamber where humidity and temperature can be controlled precisely while the specimen is prepared. The specimen is mounted on a plunger and a shutter controlled opening is opened substantially simultaneously with release of the plunger so the specimen is propelled through the shutter into an adjacent cryogenic bath.

Abstract: An improved instrument for the precise measurement of interfacial tension between two fluid phases by means of a drop of the less dense fluid surrounded by the more dense fluid, both fluids spinning together in gyrostatic equilibrium. Elements of the invention eliminate departures from gyrostatic equilibrium which went unrecognized in the prior art. These elements are based on hydrodynamic principles unknown in the prior art. The instrument is characterized by the combined use of air bearings and sample-holder mountings which reduce vibrations and eccentricities, eliminate temperature gradients within the sample, and assure that interfering hydrodynamic flows are suppressed. Other improvements include biprecision sample tube, full visual access to the spinning drop, leveling provisions, timing belt transmission, avoidance of bearing heating and wear problems, and convenient control of sample temperature.