Labelling

TET (tetrachlorofluorescein) is a green-fluorescent fluorescein derivate with absorption maximum at 519 nm and emission maximum at 535 nm. TET is spectrally similar to R6G, JOE, and VIC, widely used for labeling PCR probes. Oligonucleotides labeled with TET are often used in real-time PCR; the preparation of such oligonucleotides can be performed using click chemistry. This derivative is an azide, a pure 6-isomer, for conjugating TET to other molecules by copper-catalyzed and copper-free click reactions.

Azide derivative of red fluorescent dye TR (Texas Red, sulforhodamine 101 acid chloride) for click chemistry conjugation with terminal alkynes via a copper-catalyzed click reaction or strained cyclooctynes via a copper-free click reaction. TR is a red-fluorescent dye used for cell staining, fluorescence microscopy applications, and cell sorting with fluorescent-activated cell sorting machines. Texas Red is also commonly used in molecular biology, mainly quantitative RT-PCR and cellular assays.

Alkyne derivative of BP Fluor 488 dye for copper-catalyzed cycloaddition to azides (CuAAC). BP Fluor 488 alkyne is used for fluorescent labeling of azidated biomolecules, polymers, and surfaces. BP Fluor 488 is sulfonated rhodamine, a bright, photostable, and hydrophilic fluorophore that emits in the green channel (absorption max. is at 495 nm, emission max. is at 519 nm).

BP Fluor 568 alkyne derivate is an effective tool for labeling purposes. It is easily detected in the ROX channel with a high signal-to-noise ratio in different biological samples. Besides, BP Fluor 568 alkyne is water soluble and insensitive to pH changes between pH 4 and pH 10. Mild reaction conditions are suitable for most biomolecules, cells, and tissues. Bioconjugation with BP Fluor 568 alkyne presents a powerful technique for the production of fluorescently labeled biomolecules. BP Fluor 568 alkyne is recommended for visualization procedures, including fluorescence microscopy, flow cytometry, and other applications where label brightness and photostability are required.

JOE dye is a fluorophore similar to TET, but less hydrophobic. The dye is often used for the labeling of nucleic acids. JOE alkyne can be conjugated with azides using copper catalyzed Click chemistry reaction.

ROX alkyne is an alkyne derivative of the bright red-emitting dye ROX (Rhodamine X, Rhodamine 101). Due to its quantum yield approaching unity, ROX is a popular dye for qPCR and microscopy applications. It is used for fluorescent labeling of azide-containing biomolecules via copper-catalyzed click reaction. This product is a pure 6-isomer of ROX. ROX is prone to oxidation; therefore, its derivatives should preferably be stored in an inert atmosphere.

Thiol-reactive, near infrared dye Cyanine7.5 for the labeling of protein SH groups, an analog of Cy7.5® maleimide. Most proteins contain sulfhydryl groups which can be selectively labeled with maleimides. With this reagent, these proteins can be converted to near infrared (NIR) fluorescent conjugates. After it, the conjugates can be used in non-invasive live organism imaging to study distribution of the protein in tissues and organs.

BP Fluor 430 hydrazide is a chemical reagent containing the BP Fluor 430 dye and a hydrazide group. Hydrazides can readily react with aldehydes such as those found on aldose-type sugars to form hydrazone bonds. BP Fluor 430 is a green fluorescent dye with excitation and emission maxima at 430 nm and 539 nm respectively.

sulfo-Cyanine5 is a sulfated derivative of Cyanine5 dye, well soluble in water because of two negatively charged sulfo groups in its structure. By its spectral characteristics, this far-red fluorescent dye is an analog of Cy5. Hydrazides efficiently react with aldehydes and ketones resulting in hydrazones, so this compound can be used for conjugation with carbonyl derivatives of biomolecules. The reaction runs in aqueous conditions, which is important when working with antibodies and proteins. Cys-diol groups in sugars in glycosylated proteins and antibodies can be oxidized into dialdehydes, and cysteine in proteins can be converted with enzymes to formyl glycerol (i. e. reactive groups for conjugation with sulfo-Cyanine5 hydrazide). Carboxyl groups of aspartic and glutamic acids in proteins and peptides can be also conjugated with sulfo-Cyanine5 hydrazide in the presence of activating agents: carbodiimide (EDAC) or methyl morpholine (DMTMM) derivatives.