Atto-conjugated anti-human primary antibodies are fluorescent immunoreagents utilizing a premium family of synthetic dyes known for exceptional brightness, narrow emission spectra, and outstanding photostability. Produced by immunizing hosts such as goat, rabbit, mouse, or rat with purified human immunoglobulins or specific human proteins, the antibodies are affinity-purified and covalently linked to Atto fluorophores via NHS-ester or maleimide chemistries. The Atto series spans the ultraviolet to near-infrared spectrum, with commonly available variants including Atto 390 (violet), Atto 488 (green), Atto 565 (orange), Atto 594 (red-orange), Atto 633 (red), Atto 647N (far-red), Atto 680 (near-IR), and Atto 700 (near-IR).
Atto dyes exhibit superior performance characteristics: high quantum yields (0.5–0.9), exceptional photostability enabling prolonged imaging and super-resolution techniques, narrow emission spectra minimizing spectral overlap in multicolor panels, excellent water solubility preventing aggregation, and fluorescence stability across a broad pH range (2–10). Atto 647N, a far-red variant, serves as a robust alternative to Cy®5 and Alexa Fluor® 647 with enhanced brightness and superior resistance to photobleaching. Available specificities include anti-human IgG (H+L), anti-human IgG (Fc), isotype-specific reagents (IgG1–IgG4, IgA, IgM, IgE, IgD), and anti-human CD markers, cytokines, and signaling proteins. Extensive cross-adsorption eliminates nonspecific binding.
Applications
Atto conjugates are employed across advanced fluorescence-based platforms. In confocal and super-resolution microscopy (STED, single-molecule localization), exceptional photostability supports prolonged imaging, z-stack acquisition, and nanometric resolution (30–50 nm). In flow cytometry and FACS, high brightness and narrow emission spectra enable detection of low-abundance human antigens in multicolor panels with minimal compensation. In immunohistochemistry, these conjugates facilitate antigen localization in human tissues with reduced background autofluorescence. Additional applications include high-content screening, fluorescent Western blotting, Luminex® multiplex assays, and in vivo near-infrared imaging.
Working dilutions range from 1:100 to 1:2,000 depending on dye variant and application. Store at 4°C, protected from light; do not freeze. Intended for research use only.
