Abstract: Photoresponsive devices including a photoresponsive electrode are provided, and methods for their use to measure changes in environment at a site at or about the surface of the photoresponsive device. By employing a source of light for irradiating a site on the surface and means for biasing the photoresponsive electrode in relation to a counterelectrode, a variation in electrical signal can be related to a change in a medium in photoresponsive modulation relationship to the photoresponsive electrode surface.

Abstract: Methods and apparatus are disclosed for detecting the effects of cell affecting agents on living cells. The method steps include providing living cells that are retained in a micro flow chamber. The micro flow chamber is adapted for either continuous or intermittent flow of solutions or suspensions in intimate contact with the cells. The solutions or suspensions, which contain a cell affecting agent, are then flowed in intimate contact with the cells and the pit is measured.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Methods are disclosed for detecting the effects of cell affecting agents on living cells. The method steps include providing living cells that are retained in a micro flow chamber. The micro flow chamber is adapted for either continuous or intermittent flow of solutions or suspensions in intimate contact with the cells. The solutions or suspensions, which contain a cell affecting agent, are then flowed in intimate contact with the cells and at least one effect of the cell affecting agent on the cells is measured by an appropriate detecting means, which is operatively associated with the micro flow chamber.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Methods and apparatuses are described for determining the presence of an analyte in a sample suspected of containing the analyte. The method comprises contacting a concentrate of a determinable element capable of being detected by means of a semiconductive electrode with the electrode in the presence of a relatively large volume of an assay medium. The determinable element is present in the concentrate in the amount related to the amount of analyte present in the sample. The volume of the medium in diffusive communication with the concentrate is then reduced and the determinable element is detected by means of the effect that the determinable element has on the semiconductive electrode.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: An apparatus for determining a characteristic of a signal modulating component related to an analyte of interest at an assay site by measuring light modulated by the component. A light source uniformly illuminates the assay site and a reference site. The light is directed from the sites onto a group of memory cells on the surface of a random access memory. The memory cells will decay from a logical 1 to a logical 0 due to the light over a period of time which is a function of the intensity of the light and the reference voltage of the memory cells marking the difference between a 1 and a 0. The digital state of each of the memory cells in the group is measured a predetermined exposure time. The measured states of a group of memory cells corresponding to the assay site are compared to the memory cell states for a reference group. The measured states are then analyzed to determine a characteristic of the analyte.

Abstract: Devices and methods are provided for making a plurality of determinations of the local (site-specific) redox state of a liquid system, by employing a photoresponsive element, which can be independently irradiated at different sites to provide independently detectable signals.

Abstract: Photoresponsive devices, including a photoresponsive electrode, are provided and methods for their use to measure changes in environment at a site at or about the surface of the photoresponsive device. By employing a source of light for irradiating a site on the surface and means for biasing the photoresponsive electrode in relation to a counterelectrode, a variation in electrical signal can be related to a change in a medium in photoresponsive modulation relationship to the photoresponsive electrode surface.