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.

Compositions and methods of synthesizing near IR, closed chain, sulfo-cyanine dyes are provided.

This current disclosure is directed to charge-transfer heptamethine dyes for NIR singlet oxygen generation, each such dye comprising a near-infrared (NIR) absorbing dye having heptamethine linkages orthogonally coupled to an optionally substituted cationic heteroaryl ring moiety as a charge-transfer partner and uses thereof.

The near-infrared window of fluorescent heptamethine cyanine dyes greatly facilitates biological imaging because there is deep penetration of the light and negligible background fluorescence. But dye instability, aggregation, and poor pharmacokinetics are current drawbacks that limit performance and the scope of possible applications. All these limitations are simultaneously overcome with a new molecular design strategy that produces a charge balanced and sterically shielded fluorochrome. The key design feature is a meso-Aryl group that simultaneously projects two shielding arms directly over each face of a linear heptamethine polyene. Cell and mouse imaging experiments compared a shielded heptamethine cyanine dye (and several peptide and antibody bioconjugates) to benchmark heptamethine dyes and found that the shielded systems possess an unsurpassed combination of photophysical, physiochemical and biodistribution properties that greatly enhance bioimaging performance.

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.

A process for the preparation of substantially pure Indocyanine green of formula with purity greater than 99.0% is provided. More particularly, the embodiments relate to the process for the preparation of Indocyanine green of formula and its intermediates thereof. It further provides crystalline form I of Indocyanine green of formula and process thereof.

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

Provided is a modified J-aggregate (MJ). In some embodiments, the MJ is nanoscale, sub-micronscale, or microscale. Also provided is an MJ conjugate. Also provided are processes for making an MJ or an MJ conjugate. Photoacoustic imaging methods employing the MJ or MJ conjugate are also provided.

There are provided a compound of Formula (1) and a labeled biological substance having the compound.

##STR00001##

R.sup.1 to R.sup.6, R.sup.11 to R.sup.13, and R.sup.22 to R.sup.29 represent specific groups, and n is an integer of 1 to 3.

One selected from R.sup.1, R.sup.2, R.sup.5, R.sup.22 to R.sup.25 and one selected from R.sup.3, R.sup.4, R.sup.6, and R.sup.26 to R.sup.29 are bonded through a linking group LL.

The linking group LL represents a linking group having 1 to 100 atoms, which does not have any one of an aromatic hydrocarbon ring, a sulfo group, or a phosphono group.

R.sup.1, . . . , R.sup.6, R.sup.22, . . . , or R.sup.29 includes a structure represented by —(CH.sub.2—CH.sub.2—O).sub.m—, where m is 1 to 50.

The above-described compound is a neutral compound and contains at least one substituent capable of being bonded to a carboxy group or a biological substance.