A method for manipulating a cryogenic specimen for subsequent examination includes mounting a cryogenic specimen on a work surface of a specimen holder and placing the specimen holder within a pumped cryostat chamber having a layer of cryogenic liquid therein. The cryostat chamber is vented and kept at low humidity in order to generate a cryogenic vapor layer above the cryogenic liquid so that the work surface of the specimen holder is within the cryogenic vapor layer and low humidity and inert environment. The cryogenic specimen in then manipulated to a specimen carrier contained on a different portion of the work surface while keeping the cryogenic specimen within the cryogenic vapor layer.

Methods of introducing a small molecule into a crystal of a macromolecule, of obtaining a microcrystal having a macromolecule and a small molecule from a crystal of the macromolecule, of determining a structural model for a complex having a macromolecule and a small molecule, of identifying a small molecule that complexes with a macromolecule, and of screening a library of small molecules for their binding to a macromolecule are disclosed.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

Apparatus and methods for measuring the concentrations of organic and inorganic carbon, or of other materials in aqueous samples are described, having a reactor that is resistively heated by passing an electric current through the reactor.

Apparatus and methods for measuring the concentrations of organic and inorganic carbon, or of other materials in aqueous samples are described, having a reactor that is resistively heated by passing an electric current through the reactor.

A method includes introducing a fluidic sample into the void volume and onto the surface of a porous material, bringing the porous material into contact with a hydrophilic substrate compatible with a cryogenic Transmission Electron Microscope, separating the porous material from the substrate, and transferring a portion of the sample from the porous material to the substrate between their contact and separation.

A method includes introducing a fluidic sample into the void volume and onto the surface of a porous material, bringing the porous material into contact with a hydrophilic substrate compatible with a cryogenic Transmission Electron Microscope, separating the porous material from the substrate, and transferring a portion of the sample from the porous material to the substrate between their contact and separation.

A closed-loop temperature controller employing at least two sensors: a control temperature sensor and a safety sensor at the heat-transfer element. The heat-generating element is separated from the controlled mass/volume by a transport delay so that the mass or volume that is being heated or cooled is located in a vessel which is located remotely from the heat-transfer unit. Thermally conducting fluid flows through a conduit that connects the heat-transfer unit to the vessel. Upon fluid flow interruption or control sensor removal, the temperature controller quickly detects thermal runaway before the safety sensor has reached the critical temperature. In heated systems, the temperature controller will therefore minimize direct damage and/or overshoot damage caused by excessive heat. It will also maintain the heater's output at an elevated, but non-damaging level to enable a fast recovery to the original setpoint temperature after the nonlinearity subsides.

A closed-loop temperature controller employing at least two sensors: a control temperature sensor and a safety sensor at the heat-transfer element. The heat-generating element is separated from the controlled mass/volume by a transport delay so that the mass or volume that is being heated or cooled is located in a vessel which is located remotely from the heat-transfer unit. Thermally conducting fluid flows through a conduit that connects the heat-transfer unit to the vessel. Upon fluid flow interruption or control sensor removal, the temperature controller quickly detects thermal runaway before the safety sensor has reached the critical temperature. In heated systems, the temperature controller will therefore minimize direct damage and/or overshoot damage caused by excessive heat. It will also maintain the heater's output at an elevated, but non-damaging level to enable a fast recovery to the original setpoint temperature after the nonlinearity subsides.