autofluorescence

Direct Blue 1 (Pontamine sky blue), a counterstain for background autofluorescence in immunofluorescence histochemistry, structurally resembles glutamate and operates as a potent, competitive VGLUT inhibitor, not impacting plasma membrane transporters. This compound stands out as the inaugural small molecule PrP ligand to inhibit Aβ binding.

Tetra-sulfo-Cy7 DBCO is a bright and photostable near-infrared probe. As a water-soluble hydrophilic dye, Cy7 DBCO is the preferred reagent for applications requiring minimal nonspecific binding and exceptionally high brightness. Its fluorescence remains stable across a pH range of 4 to 10 and exhibits minimal autofluorescence within biological samples in this spectral range. Although the fluorescence of this long-wavelength cyanine dye is not visible to the naked eye, most imaging systems can easily detect it.

INDO 1 pentasodium functions as a ratiometric, free calcium ion (Ca2+) fluorescent indicator, capable of quantitatively tracking the dynamic changes in intracellular free Ca2+ concentration. In its free state, when unbound to Ca2+, INDO 1 pentasodium emits light at a peak of 485 nm upon excitation by ultraviolet light at 350 nm. When bound to Ca2+, the emission peak shifts to 405 nm. INDO 1 pentasodium exhibits considerable photoinstability, being prone to photobleaching, and its emission spectrum may overlap with the autofluorescence of NADH.

BODIPY 630/650 Maleimide is a far-red fluorescent probe and the maleimide derivative of BODIPY 630/650. The maleimide group enables covalent conjugation with thiol (-SH) groups on proteins, peptides, and other biomolecules, forming stable thioether bonds for site-specific labeling. This dye features high quantum yield, narrow emission peak, and excellent photostability. Its far-red emission reduces interference from biological autofluorescence, making it widely used for protein labeling, cellular imaging, and multichannel fluorescence analysis.

BODIPY 650/665 Carboxylic Acid is a far-red fluorescent dye featuring a carboxyl functional group. It consists of a BODIPY (boron-dipyrromethene) fluorescent core with a carboxylic acid moiety, exhibiting excitation/emission maxima of approximately 646/664 nm. Its long-wavelength emission effectively minimizes interference from biological autofluorescence, making it suitable for deep-tissue imaging applications.

Sulfo-Cy7 Alkyne is a near-infrared fluorescent dye containing an alkyne functional group, which enables highly selective conjugation to azide-modified biomolecules via copper-catalyzed azide–alkyne cycloaddition (CuAAC). As a sulfonated Cy7 derivative, it emits in the near-infrared window, reducing autofluorescence from biological samples and improving tissue imaging performance. Sulfo-Cy7 alkyne is commonly used for bioorthogonal labeling and in vivo imaging probe construction, with application conditions optimized according to the experimental system.

Me-Tetrazine-Cyanine5.5 is a near-infrared fluorescent probe and the methyl-tetrazine functionalized derivative of Cyanine5.5. Its methyl-tetrazine group reacts rapidly and with high selectivity with TCO-modified proteins, antibodies, or other biomolecules via inverse electron-demand Diels–Alder (IEDDA) chemistry, forming stable covalent conjugates without a catalyst. Emitting in the near-infrared window, this dye reduces biological autofluorescence and improves tissue imaging performance. Me-Tetrazine-Cyanine5.5 is widely used for bioorthogonal labeling, cellular and tissue imaging, protein tracking, and multicolor fluorescence analysis studies.

Europium W1024 isothiocyanate (ITC) is a lanthanide-based fluorophore characterized by its long emission lifetime and significant Stokes shift, featuring excitation and emission maxima at 340 and 613 nm, respectively. This compound includes a reactive isothiocyanate handle that engages with primary amino groups in alkaline conditions. It maintains stability under high temperatures, in the face of elevated EDTA concentrations, or at low pH levels, though it falters when exposed to manganese. Commonly, Europium W1024 ITC serves as a donor fluorophore in time-resolved fluorescence resonance energy transfer (TR-FRET) applications, offering the advantage of a prolonged measurement window for observing acceptor fluorescence and minimizing autofluorescence interference through its extended emission lifetime.

Cyanine5.5 Maleimide is a near-infrared fluorescent probe and the maleimide derivative of Cyanine5.5. Its maleimide group covalently reacts with thiol (-SH) groups on proteins, antibodies, and other biomolecules to form stable thioether bonds. Emitting in the near-infrared window, this dye reduces biological autofluorescence and improves tissue imaging performance. Cyanine5.5 maleimide is widely used for in vivo small-animal imaging probe construction, protein labeling, and flow cytometry studies.