1030 results about "Fluorescein" patented technology

Disclosed is a device and methods for the rapid chemiluminescence assay of surfaces to detect the presence of microbial contamination. The device and methods are suitable for use by untrained personnel under the relatively harsh and variable conditions found in the field, for example in fast food restaurants and other food preparation areas. The chemiluminescence reaction that is the source of the analytical signal in the disclosed assay device and method is preferably based on a luciferase / luciferin system.

The present invention provides methods, compositions, substrates, and kits useful for analyzing the metabolic activity in cells, tissue, and animals and for screening test compounds for their effect on cytochrome P450 activity. In particular, a one-step and two-step methods using luminogenic molecules, e.g. luciferin or coelenterazines, that are cytochrome P450 substrates and that are also bioluminescent enzyme, e.g., luciferase, pro-substrates are provided. Upon addition of the luciferin derivative or other luminogenic molecule into a P450 reaction, the P450 enzyme metabolizes the molecule into a bioluminescent enzyme substrate, e.g., luciferin and / or luciferin derivative metabolite, in a P450 reaction. The resulting metabolite(s) serves as a substrate of the bioluminescent enzyme, e.g., luciferase, in a second light-generating reaction. Luminescent cytochrome P450 assays with low background signals and high sensitivity are disclosed and isoform selectivity is demonstrated. The present invention also provides an improved method for performing luciferase reactions which employs added pyrophosphatase to remove inorganic pyrophosphate, a luciferase inhibitor which may be present in the reaction mixture as a contaminant or may be generated during the reaction. The present method further provides a method for stabilizing and prolonging the luminescent signal in a luciferase-based assay using luciferase stabilizing agents such as reversible luciferase inhibitors.

Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 μm, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.