Abstract: The present disclosure is directed to a reactive ester agent capable of conjugating a reporter molecule to a carrier molecule or solid support. The reactive ester agent has the general formula: wherein the variables are described throughout the application.

Abstract: A new class of pH sensitive fluorescent dyes and assays relating thereto are described. The dyes and assays are particularly suited for biological applications including phagocytosis and monitoring intracellular processes. The pH sensitive fluorescent dyes of the present invention include compounds of Formula I: wherein the variables are described throughout the application.

Abstract: The present invention provides methods and fluorescent compounds that facilitate detecting and labeling of a fusion protein by being capable of selectively binding to an affinity tag. The fluorescent compounds have the general formula A(B)n, wherein A is a fluorophore, B is a binding domain that is a charged chemical moiety, a protein or fragment thereof and n is an integer from 1-6 with the proviso that the protein or fragment thereof not be an antibody or generated from an antibody. The present invention provides specific fluorescent compounds and methods used to detect and label fusion proteins that contain a poly-histidine affinity tag. These compounds have the general formula A(L)m(B)n wherein A is a fluorophore, L is a linker, B is an acetic acid binding domain, m is an integer from 1 to 4 and n is an integer from 1 to 6.

Abstract: The present invention relates to compounds that are substrates for an enzyme, and upon reaction with the enzyme provide a detectable response, such as an optically detectable response. In particular, the compounds have utility in detecting the presence of a ?-lactamase in a sample. In addition to the compounds, methods are disclosed for analyzing a sample for the presence of a ?-lactmase, for example, as an indicator of expression of a nucleic acid sequence including a sequence coding for a ?-lactmase. Kits are disclosed that include the disclosed compounds and additional components, for example, cells, antibodies, a ?-lactmase or instructions for using the components in an assay.