Methods of analyzing purity of compositions comprising cysteamine and detecting impurities in cysteamine compositions are described.

A detection device for detecting analytes in liquid specimen is provided. The detection device comprises: a specimen chamber for collecting or storing a liquid specimen; a detecting chamber for containing a detecting element; and a through hole for transferring the liquid specimen between the specimen chamber and the detecting chamber. The through hole can be opened or self-sealed. The sealing or opening of the through hole controls whether or not the liquid specimen in the specimen chamber enters the detecting chamber via the through hole. Furthermore, a detection method is provided.

Disclosed herein is a fluorescent compound represented by the following general formula and having fluorescence characteristics that vary in the presence of a subject substance,

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wherein R.sub.1 and R.sub.2 each independently represent a carboxyl group, or a substituent containing a carboxyl group, and R.sub.3 and R.sub.4 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, a carboxyl group, or a substituent containing a carboxyl group.

A personal-sized, portable explosive detection field test kit (ETK) and related methods of use. Embodiments of the disclosed ETK include a case having a closing system featuring three levels of closure which retain the case cover securely in a closed position until ready for use, while being easily opened when necessary. The ETK instructions are permanently attached to the case to prevent loss. The case includes retention features which retain the kit components until needed and protects them against loss or damage. The ETK includes one or more test tubes that are color coded and include abbreviated instructions.

The invention relates to an activated form of procaine, and the use of the activated procaine, or salts or solvates thereof, to label amine-containing compounds. In some embodiments, the amine-containing compound is an N-glycan.

A method for analyzing one or more nitrogen-containing compounds is disclosed. In the method, a ninhydrin-containing composition is irradiated with UV light in an activation zone to produce a ninhydrin reagent containing hydrindantin. The ninhydrin reagent is passed to a reaction zone. In the reaction zone the ninhydrin reagent is contacted with the nitrogen-containing compounds.

In one aspect, methods of sensing are described herein. In some embodiments, a method of sensing comprises disposing a fluorophore in a biological environment, wherein the fluorophore comprises a dioxo-pyridine ring (DPR) or a thiazolopyridine acid (TPA). The method further comprises exposing the biological environment to electromagnetic radiation having a wavelength corresponding to an excitation wavelength of the fluorophore, detecting light emitted by the fluorophore, and correlating the light emitted by the fluorophore to a presence or absence of an analyte within the biological environment in an amount above a minimum detection threshold. The presence of the analyte can increase or decrease the amount of light emitted by the fluorophore. The presence of the analyte may also shift the peak emission wavelength or alter the fluorescence lifetime of the fluorophore. The analyte, in some embodiments, comprises hydrogen ions, halide ions, and/or halogens.

An anise flavored liquid medication. The liquid medication contains phenylephrine and an anethole analog that is substantially free of aldehyde groups. In one example, the anethole analog can be 1-methoxy-4-n-propylbenzene.

A solid phase reagent and method for simultaneously capturing and fluorescently labeling an analyte with multiple reactive sites to provide a mono-labeled analyte are disclosed. The reagent can be used in the method and comprises a plurality of analyte-reactive groups tethered to a porous solid phase, wherein each analyte-reactive group is covalently attached to a fluorescent group either directly or indirectly, wherein the distance between adjacent analyte-reactive groups is greater than the gyration radius of a captured analyte; the fluorescent group is covalently attached to a cleavable anchor group either directly or through a first spacer; and the cleavable anchor group is covalently attached to the solid phase either directly or through a second spacer, wherein the solid phase is a porous solid or a porous gel.

The present disclosure relates to a composition for cell imaging including a probe compound, and a method of cell-material imaging using the same. The composition for cell imaging and the method of cell-material imaging are provided to image the material in the cell by measuring fluorescence generated by reacting the probe and a material in a cell.