Cyanine heptamethine dyes are well-known NIR fluorophores, with emission wavelengths >740 nm, and often are reagents of choice for labeling antibodies. Two of the most popular commercial NIR cyanine heptamethine dyes for antibody conjugation are IRDye 800CW and DyLight 800. While these NIR dyes are undoubtedly useful for many types of immunofluorescence technologies, the resulting NIR dye-labeled antibodies sometimes exhibit performance limitations due to three inherent fluorophore concerns. (1) A meso-OAryl group connected directly to the heptamethine fluorochrome group is susceptible to nucleophilic displacement by biological amines and thiols^{1, 2} resulting in a diminished chemical stability of the dye-antibody conjugates during synthesis, storage, or the time-course of an imaging experiment. In addition, the electron-donating meso-OAryl group promotes high fluorochrome reactivity with electrophilic singlet oxygen, resulting in relatively poor dye photostability.^3,4 (2) Both dyes are flat molecules with a hydrophobic core and a polyanionic charge periphery. Thus, the chemical conversion of a small polar, cationic lysine residue on the antibody surface to a large hydrophobic, polyanionic dye derivative has the potential to produce substantial changes in antibody folding and physiochemical properties, leading to lower antibody stability and decreased target specificity.^4-8 (3) When activated versions of these hydrophobic dyes are conjugated to an antibody surface, they tend to attach at the proximal lysine sites as stacked face-to-face dimers, which produces a diagnostic H-dimer peak in the absorbance spectra that is nonfluorescent.^8,9 Moreover, the close stacking of proximal conjugated IRDye 800CW or DyLight800 on an antibody surface amplifies the potential for a deleterious effect on antibody targeting because of a localized patch of polyanionic charge and hydrophobicity.

In order to address these drawbacks of commercially NIR cyanine a conceptually new class of sterically shielded NIR dyes was developed in Dr. Bradley D. Smith laboratory.^{10, 11} These dyes contain two shielding PEG arms directly over both faces of the heptamethine fluorochrome blocking any undesired bimolecular association processes and thus enhance the fluorescence brightness. A recently published antibody labeling study clearly demonstrated 1-2 order of magnitude increase in brightness compared to commercially available NIR dyes as a result of almost complete prevention of stacking of multiple fluorophores appended to the antibody surface.^{10, 11}

These sterically shielded NIR dyes with greatly improved chemical and photochemical stability and substantially enhanced brightness will enable researchers to greatly improve various types of indirect NIR immunofluorescence imaging and diagnostics applications that require high sensitivity and also develop new photonintense techniques that require high photostability.

MB 800Z is a zwiteroinic, charge-balanced dye with an equal number of anionic sulfonate and cationic ammonium residues, a structural feature that is known to reduce interactions with off -target biological surfaces.

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Specifications

The post AZDye 800 Picolyl Azide appeared first on VectorLabs.

AZDye™ 633 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

AZDye™ 633 Azide is a bright and photostable far-red fluorescent probe with excitation ideally suited to the 633 nm or 635 nm laser excitation source. AZDye™ 633 Azide is water-soluble, pH-insensitive from pH 4 to pH 10. AZDye™ 633 spectrally is almost identical to Alexa Fluor® 633, DyLight® 633 or CF® 633 Dye. Combination of superior brightness and very low autofluorescence background signal in most biological samples in far-red spectral region allows for very sensitive detection of alkyne-labeled biomolecules.

[caption id="attachment_27033" align="alignnone" width="1000"] Abs/Em Spectra[/caption]

Specifications

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AZDye™ 680 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

[caption id="attachment_24263" align="alignnone" width="1940"] Abs/Em Spectra[/caption]

Specifications

The post AZDye 680 Picolyl Azide appeared first on VectorLabs.

AZDye 660R Picolyl Azide is a bright and very photostable probe routinely used for imaging of alkyne-containing biomolecules. MB 660R Azide can be reacted with terminal alkynes via a copper-catalyzed click reaction (CuAAC). It also reacts with strained cyclooctyne via a copper-free “click chemistry” reaction to form a stable triazole and does not require Cu-catalyst or elevated temperatures. The brightness and photostability of this dye are best suited to direct imaging of low-abundance targets.

AZDye 660R is a bright and photostable far-red dye that emits fluorescence at about 685 nm in the borderline spectral region between far-red and near-IR. Although the absorption maximum is at around 665 nm, this dye can be sufficiently excited by the 633 or 635 nm laser. AZDye 660R dye is water soluble and pH-insensitive from pH 4 to pH 10. AZDye 660R is a rhodamine-based dye, and like rhodamine dyes in general, it is exceptionally photostable (Figure 1). The superior photostability and excellent brightness of AZDye 660R make the dye an ideal choice for confocal microscopy and other demanding applications.

[caption id="attachment_26345" align="alignnone" width="1000"] Abs/Em Spectra[/caption]

Specifications

The post AZDye 660R Picolyl Azide appeared first on VectorLabs.

Cy7 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

In summary, the introduction of a copper-chelating motif into azide probe leads to a substantial increase in the sensitivity and reduced cell toxicity of CuAAC detection alkyne-tagged biomolecules. This will be of special value for the detection of low abundance targets or living system imaging.

Cy7 Picolyl Azide is a bright and photostable near-IR probe that is spectrally similar to Alexa Fluor® 750, DyLight® 750, and IRDye® 750 dye. Cy7 Picolyl Azide is water-soluble, hydrophilic dye often a reagent of choice for assay where minimal non-specific binding and exceptional brightness is required. The fluorescence of Cy7 dye is pH insensitive from pH 4 to pH 10 and produces minimal autofluorescence of biological specimens in this region of the spectrum. Fluorescence of this long-wavelength Cyanine dye is not visible to the human eye but is readily detected by most imaging systems.

[caption id="attachment_24150" align="alignnone" width="1000"] Abs/Em Spectra[/caption]

Specifications

The post Cy7 Picolyl Azide appeared first on VectorLabs.

Cy5.5 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

In summary, the introduction of a copper-chelating motif into azide probe leads to a substantial increase in the sensitivity and reduced cell toxicity of CuAAC detection alkyne-tagged biomolecules. This will be of special value for the detection of low abundance targets or living system imaging.

Cy5.5 Picolyl Azide is a bright and photostable near-IR probe that spectrally similar to Alexa Fluor® 680, DyLight® 680, and IRDye® 680 dye. The fluorescence of Cy5.5 dye is pH insensitive from pH 4 to pH 10 and produces minimal autofluorescence of biological specimens in this region of the spectrum. Fluorescence of this long-wavelength Cyanine dye is not visible to the human eye but is readily detected by most imaging systems.

[caption id="attachment_24263" align="alignnone" width="1940"] Abs/Em Spectra[/caption]

Specifications

The post Cy5.5 Picolyl Azide appeared first on VectorLabs.

Cy3 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

In summary, the introduction of a copper-chelating motif into azide probe leads to a substantial increase in the sensitivity and reduced cell toxicity of CuAAC detection alkyne-tagged biomolecules. This will be of special value for the detection of low abundance targets or living system imaging.

Cy3 Picolyl Azide is a water-soluble, bright orange-fluorescent dye with excitation ideally suited for the 532 nm or 555 nm laser lines and visualized with TRITC (tetramethylrhodamine) filter sets. Cy3 dye is structurally similar, and spectrally is almost identical to Alexa Fluor® 555, CF® 555 Dye, or any other Cyanine3 based fluorescent dyes.

[caption id="attachment_24113" align="alignnone" width="661"] Abs/Em Spectra[/caption]

Specifications

The post Cy3 Picolyl Azide appeared first on VectorLabs.

AZDye™ 594 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

In summary, the introduction of a copper-chelating motif into azide probe leads to a substantial increase in the sensitivity and reduced cell toxicity of CuAAC detection alkyne-tagged biomolecules. This will be of special value for the detection of low abundance targets or living system imaging.

5-TAMRA (also known as TAMRA, isomer 5) is the red-fluorescent probe that is compatible with various excitation sources including mercury arc, tungsten and xenon arc lamps, the 544 nm line of the Helium-Neon laser and the 532 nm green laser line.

[caption id="attachment_24144" align="alignnone" width="1000"] Abs/Em Spectra[/caption]

Specifications

The post 5-TAMRA Picolyl Azide appeared first on VectorLabs.

AZDye™ 350 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

In summary, the introduction of a copper-chelating motif into azide probe leads to a substantial increase in the sensitivity and reduced cell toxicity of CuAAC detection alkyne-tagged biomolecules. This will be of special value for the detection of low abundance targets or living system imaging.

AZDye™ 350 is a water-soluble moderately photostable, blue-fluorescent probe optimally excited by the 350 nm laser line. It is routinely used for generation of stable signal in imaging and flow cytometry. The brightness and photostability of blue dyes are best suited to direct imaging of high-abundance targets.

[caption id="attachment_23916" align="alignnone" width="1200"] Abs/Em Spectra[/caption]

Specifications

The post AZDye 350 Picolyl Azide appeared first on VectorLabs.

AZDye™ 594 Picolyl Azide is an advanced fluorescent probe that incorporates a copper-chelating motif to raise the effective concentration of Cu(I) at the reaction site to boost the efficiency of the CuAAC reaction, resulting in a faster and more biocompatible CuAAC labeling. Up to 40-fold increase of signal intensity, compared to conventional azides, was reported (see Selected References).

In addition, the use picolyl azides instead of conventional azides allows for at least a tenfold reduction in the concentration of the copper catalyst without sacrificing the efficiency of labeling, significantly improving biocompatibility of CuAAC labeling protocol.

AZDye™ 594 is bright, water-soluble, and pH-insensitive from pH 4 to pH 10 red-fluorescent dye with absorption and emission maxima at 590 and 617 nm, respectively. It can be used with the 561 nm and 594 nm laser lines. AZDye™ 594 dye structurally is identical to Alexa Fluor® 594. Its absorption/emission spectra is a perfect match to spectra of many other fluorescent dyes based on sulfonated rhodamine core, including CF® 594 Dye, DyLight® 594 and Alexa Fluor® 594.

[caption id="attachment_25875" align="alignnone" width="1000"] Abs/Em Spectra[/caption]

Specifications

The post AZDye 594 Picolyl Azide appeared first on VectorLabs.