Labelling

DusQ 2 succinimidyl ester is a derivative with an amine reactive group for labeling with the amine-modified oligonucleotides, amine-containing proteins and other molecules. DusQ 2 is a nonfluorescent quencher with an absorbance maximum of 552 nm. It is useful as an acceptor in fluorescence resonance energy transfer (FRET) applications, nucleic acid assays in conjunction with yellow and orange to red emitting dyes such as Cyanine3, Cyanine5, ROX, Texas Red, AF 555, AF 594, AF 647. NHS ester function allows to conjugate the quencher to various biomolecules of interest, and also to prepare oligonucleotides with DusQ 2.

DusQ 21 is a dark quencher used as an acceptor in FRET applications, it has absorption maximum 656 nm, and can be used in multiplex assays due to the lack of secondary fluorescence. It is a quencher of choice for pairing with fluorescent dyes that emit in the red and near-infrared part of the range. DusQ 21 NHS ester derivative is used for labeling with the primary amines of amine-containing molecules. It can be used for quenching of many fluorophores, including Cyanine5, Cyanine5.5, AF 647.

DusQ 3 NHS ester is a dark, far-red nonfluorescent DusQ 3 derivative for labeling with the primary amines of proteins, modified oligonucleotides. The labeling with covalent amide bond occurs most efficiently at pH 7-9. DusQ 3 is used as an acceptor for preparation of fluorogenic dual-labeled probes, for qPCR, sequencing and other fluorescence-quenched system applications. Due to quenching range characterised as 620-730 nm DusQ 3 is useful as an acceptor in fluorescence resonance energy transfer (FRET) combined with far-red to near-IR emitting dyes such as Cyanine5, Cyanine5.5, AF 647.

HEX NHS ester, 6-isomer is an amine-reactive dye for labeling of amine groups in proteins, peptides, amino-modified oligos, and other target molecules. HEX is a hexachlorinated derivate of the fluorescent dye fluorescein. HEX exhibits an excitation peak at 533 nm and an emission peak at 549 in the green-yellow area. It can serve as a substitute for JOE, BODIPY™ 530/550, VIC™ because of their similar spectral characteristics. HEX NHS ester is widely used in nucleic acid sequencing, PCR/qPCR, and related research.

JOE is a fluorescein-derived xanthene dye containing methoxy groups and chlorine atoms. Its absorption and emission spectra are between FAM and TAMRA/ROX channels. For this reason, this fluorophore is often used for multiplex detection, including DNA sequencing. This derivative is an activated N-hydroxysuccinimide ester used to label proteins, peptides, amino-modified oligonucleotides, and other target molecules via conjugation with amines.

BP Fluor 488 is a fluorescent dye. BP Fluor 488 is a fluorophore pH-insensitive over a broad pH range (from 4 to 10). It has an absorption maximum at 495 nm and an emission maximum at 519 nm in the green spectrum region. The dye is hydrophilic and can be used to introduce the fluorescent label into various molecules, including proteins and antibodies. Conjugates of molecules with BP Fluor 488 have high brightness and photostability and are commonly used in flow cytometry and microscopy. This allows the detection of biological objects with high sensitivity at a longer imaging time. BP Fluor 488 Propyl azide interacts with alkynyl derivatives of biomolecules in Click Chemistry reactions either in the presence of copper (I) catalyst (with terminal alkynes) or without catalyst (with cyclooctynes), leading to the formation of stable adducts.

AMCA azide for сlick сhemistry conjugation with terminal alkynes via a copper-catalyzed click reaction or strained cyclooctynes via a copper-free click reaction. AMCA (aminomethylcoumarin acetate) is one of the brightest blue fluorescent dyes. This fluorophore has a relatively large Stoke’s shift, high resistance to photobleaching, and pH-independent fluorescence from pH 4 to 10. AMCA is a widely used fluorophore for multiple-color labeling due to its minimal fluorescence overlap with green- and longer wavelength-emitting fluorescent dyes.

Cyanine3B azide for click chemistry conjugation with terminal alkynes via a copper-catalyzed click reaction or strained cyclooctynes via a copper-free click reaction. Cyanine3B is a yellow-emitting cyanine dye that is an improved version of the Cyanine3 fluorophore with significantly higher fluorescence quantum yield and photostability. Due to the fixed conformation, Cyanine3B has the highest emission quantum yield compared to other dyes of this wavelength. This is a non-sulfonated dye that requires an organic co-solvent (DMF, DMSO, or other) for efficient labeling in water.

Phenylethynylpyrene (PEP) fluorophore is a polyaromatic hydrocarbon label with high sensitivity to microenvironment. Similarly to pyrene, PEP dye readily forms excimers. However, PEP fluorescence is more red-shifted. PEP can be used as microenvironment probe, and as a label for assays based on excimer formation. This reagent contains triethyleneglycol linker to facilitate dissolution of non-polar PEP dye in organo-aqueous labeling reaction mixtures. With this azide, and click chemistry, it is easy to turn any molecule bearing alkyne into PEP-labeled probe.