Abstract: Provided are a photoactive fluorophore, a photoactive ligand, and a photoactive complex. The photoactive fluorophore includes a photoactivatable derivative of an azetidine-containing Janelia-Fluor dye. The photoactive ligand includes a photoactive fluorophore and a protein tag. The photoactive complex includes a photoactive ligand conjugated to a protein. Also provided are methods of in vivo labeling with and photoactivation of the photoactive fluorophore, ligand, and complex.

Abstract: A chemigenetic calcium indicator and a method of measuring calcium are provided. The chemigenetic calcium indicator includes a calcium-binding protein domain attached to a ligand binding protein domain. The method of measuring calcium includes administering a chemigenetic calcium indicator to a subject and determining changes in fluorescence, the chemigenetic calcium indicator including a ligand binding protein domain having a calcium-binding protein domain and a dye-ligand conjugate attached thereto.

Abstract: Fluorescent stains are described, which enable imaging of cellular structures without the need for genetic manipulation. Unique diaminobenzopyrylium dyes are disclosed, together with their use as live-cell mitochondrial stains.

Abstract: A chemigenetic calcium indicator and a method of measuring calcium are provided. The chemigenetic calcium indicator includes a calcium-binding protein domain attached to a ligand binding protein domain. The method of measuring calcium includes administering a chemigenetic calcium indicator to a subject and determining changes in fluorescence, the chemigenetic calcium indicator including a ligand binding protein domain having a calcium-binding protein domain and a dye-ligand conjugate attached thereto.

Abstract: Provided are a photoactive fluorophore, a photoactive ligand, and a photoactive complex. The photoactive fluorophore includes a photoactivatable derivative of an azetidine-containing Janelia-Fluor dye. The photoactive ligand includes a photoactive fluorophore and a protein tag. The photoactive complex includes a photoactive ligand conjugated to a protein. Also provided are methods of in vivo labeling with and photoactivation of the photoactive fluorophore, ligand, and complex.

Abstract: The presently-disclosed subject matter includes fluorescent indicators, including bright and targetable red Ca2+ indicators. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: The presently-disclosed subject matter includes fluorescent indicators, including bright and targetable red Ca2+ indicators. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: Provided herein are a voltage indicator and a method of measuring voltage. The voltage indicator includes a membrane-localized voltage-sensitive protein coupled to a capture protein. The method of measuring voltage includes administering a voltage indicator including a membrane-localized voltage-sensitive protein coupled to a capture protein, and determining changes in fluorescence of a small-molecule fluorescent dye captured by the capture protein.

Abstract: Provided herein are a voltage indicator and a method of measuring voltage. The voltage indicator includes a membrane-localized voltage-sensitive protein coupled to a capture protein. The method of measuring voltage includes administering a voltage indicator including a membrane-localized voltage-sensitive protein coupled to a capture protein, and determining changes in fluorescence of a small-molecule fluorescent dye captured by the capture protein.

Abstract: A compound of the following structure is provided:

Abstract: The presently-disclosed subject matter includes fluorescent compounds of the following formula: The compounds can be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: The presently-disclosed subject matter includes fluorescent indicators, including bright and targetable red Ca2+ indicators. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: A chemigenetic calcium indicator and a method of measuring calcium are provided. The chemigenetic calcium indicator includes a calcium-binding protein domain attached to a ligand binding protein domain. The method of measuring calcium includes administering a chemigenetic calcium indicator to a subject and determining changes in fluorescence, the chemigenetic calcium indicator including a ligand binding protein domain having a calcium-binding protein domain and a dye-ligand conjugate attached thereto.

Abstract: Provided herein are a voltage indicator and a method of measuring voltage. The voltage indicator includes a membrane-localized voltage-sensitive protein coupled to a capture protein. The method of measuring voltage includes administering a voltage indicator including a membrane-localized voltage-sensitive protein coupled to a capture protein, and determining changes in fluorescence of a small-molecule fluorescent dye captured by the capture protein.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: The presently-disclosed subject matter relates to analyte-activated photolabile compounds. The compounds include the formula: wherein Z includes a maskable molecule; L is selected from a bond, C, C(O), O, alkyl, (O)alkyl, and alkoxy; R1 is selected from H, halogen, alkyl, and acyl; each R2 is independently selected from H, alkyl, aryl, and acyl, and is optionally substituted with one or more heteroatoms independently selected from COOH and COO(alkyl); and R3 is selected from H, alkyl, aryl, halogen, CN, OH, O(alkyl), O(aryl), SH, S(alkyl), S(aryl), amine, CHO, COOH, COO(alkyl), COO(aryl), PO3H2, and SO3H, and is optionally substituted with one or more heteroatoms independently selected from N, O, and S, halogen, OH, O(alkyl), O(aryl), SH, S(alkyl), S(aryl), amine, NO2, CHO, COO, COOH, COO(alkyl), COO(aryl), C(O)NR2, PO3H2, and/or SO3H. Also provided are methods of detecting calcium and treating a subject with the analyte-activated photolabile compounds.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: Provided are a photoactive fluorophore, a photoactive ligand, and a photoactive complex. The photoactive fluorophore includes a photoactivatable derivative of an azetidine-containing Janelia-Fluor dye. The photoactive ligand includes a photoactive fluorophore and a protein tag. The photoactive complex includes a photoactive ligand conjugated to a protein. Also provided are methods of in vivo labeling with and photoactivation of the photoactive fluorophore, ligand, and complex.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.