Alexa Fluor® conjugated anti-human primary antibodies are fluorescent immunoreagents utilizing a family of highly photostable, bright, and pH-insensitive synthetic dyes for detecting human antigens across multiple spectral ranges. 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 conjugated to Alexa Fluor® dyes via NHS-ester chemistry targeting primary amines. The Alexa Fluor® series spans the entire visible and near-infrared spectrum, including Alexa Fluor® 488 (green, ex/em 495/519 nm), 555 (orange, ex/em 555/565 nm), 594 (red-orange, ex/em 590/617 nm), 647 (far-red, ex/em 650/665 nm), 680 (near-IR, ex/em 679/702 nm), and 790 (near-IR, ex/em 792/803 nm). These dyes exhibit superior properties compared to traditional fluorophores: exceptional photostability for prolonged imaging, high quantum yields (0.30–0.92 depending on variant), pH-insensitive fluorescence across pH 4–10, and excellent water solubility preventing aggregation. 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 in multi-species samples.
Applications
Alexa Fluor® conjugates are employed across multiple fluorescence-based platforms. In immunofluorescence microscopy and confocal imaging, photostability supports prolonged imaging, z-stack acquisition, and super-resolution techniques (STED, PALM, STORM). In flow cytometry and FACS, high brightness facilitates detection of low-abundance human antigens in multicolor panels with minimal compensation requirements. Additional applications include high-content screening, fluorescent Western blotting, immunohistochemistry, 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. These conjugates should be stored at 4°C, protected from light. Intended for research use only; not for diagnostic procedures.
