Protected fluorescent reagent compounds and their methods of synthesis are provided. The compounds are useful in various fluorescence-based analytical methods, including the analysis of highly multiplexed optical reactions in large numbers at high densities, such as single molecule real time nucleic acid sequencing reactions. The compounds contain fluorescent dye elements, that allow the compounds to be detected with high sensitivity at desirable wavelengths, binding elements, that allow the compounds to be recognized specifically by target biomolecules, and protective shield elements, that decrease undesirable contacts between the fluorescent dye elements and the bound target biomolecules and that therefore decrease photodamage of the bound target biomolecules by the fluorescent dye elements.

A process for detecting oil or lubricant contamination in the production of an article by adding a Stokes-shifting taggant to an oil or lubricant of a machine utilized to produce the article or a component thereof, irradiating the articles produced with a first wavelength of radiation, and monitoring the articles for emission of radiation at a second wavelength. The taggant can be in the form of a composition containing a Stokes-shifting taggant, which absorbs radiation at a first wavelength and emits radiation at a second wavelength, different from said first wavelength, dissolved or dispersed in an oil or lubricant.

Compounds used as labels with properties comparable to known fluorescent compounds. The compounds are conjugated to proteins and nucleic acids for biological imaging and analysis. Synthesis of the compounds, formation and use of the conjugated compounds, and specific non-limiting examples of each are provided.

An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength λ.sub.max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than λ.sub.max(D1) when the concentration is adjusted such that a transmittance at λ.sub.max(D1) is 10%, and λ.sub.max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength λ.sub.max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting λ.sub.max(D1) from λ.sub.max(D2) is 30 nm or more and 85 nm or less.

The present disclosure relates to new compounds and their use as fluorescent labels. The compounds may be used as fluorescent labels for nucleotides in nucleic acid sequencing applications.

The instant invention provides near-infrared fluorescent biological contrast agents and methods of using them.

A composition includes two or more near infrared absorbing compounds having an absorption maximum in a wavelength range of 650 to 1000 nm and having a solubility of 0.1 mass % or lower in water at 23° C., in which the two or more near infrared absorbing compounds include a first near infrared absorbing compound having an absorption maximum in a wavelength range of 650 to 1000 nm, and a second near infrared absorbing compound having an absorption maximum in a wavelength range of 650 to 1000 nm which is shorter than the absorption maximum of the first near infrared absorbing compound, and a difference between the absorption maximum of the first near infrared absorbing compound and the absorption maximum of the second near infrared absorbing compound is 1 to 150 nm.

Disclosed are formulations, including both liquid and lyophilized formulations, comprising a far-red dye probe and a non-linear surfactant or foamban. Also disclosed are related methods for preparing a lyophilized far-red dye probe formulation as well as related kits and diagnostic products.

The present invention relates to: a labeling dye having excellent fluorescent intensity and photostability; and a kit.

The invention provides a novel class of cyanine dyes that are functionalized with sulfonic acid groups and a linker moiety that facilitates their conjugation to other species and substituent groups which increase the water-solubility, and optimize the optical properties of the dyes. Also provided are conjugates of the dyes, methods of using the dyes and their conjugates and kits including the dyes and their conjugates.