Abstract: A system (10) and method of use for observation of microorganisms in a controlled environment is described. The system uses a diffusion gradient chamber (12) with reservoirs (24) which provide a compound or analyte (S) through a membrane (20) into a space in the chamber containing the microorganisms. The system preferably uses a camera (40) which records the observations of the microorganisms. The system enables study of microorganisms in gradients of compounds and the isolation of useful microorganisms.

Abstract: A heat transfer device particularly adapted to cool electrophoresis gels and apparatus and comprising a supporting structure and a flat plate spaced above the supporting structure by a peripheral gasket to support the plate. The flat plate, gasket and supporting structure form a shallow enclosed chamber. A pair of longitudinal apertures adjacent opposite ends of the chamber provide communication with a pair of reservoirs in the supporting structure. A pump communicates with the downstream reservoir to draw coolant fluid through the chamber at a rate of flow providing laminar flow in the fluid and drawing the flat plate and gasket tight to the supporting structure.