ATTO-conjugated anti-pig primary antibodies are directly labeled immunoreagents that pair a porcine antigen-specific immunoglobulin with a member of the ATTO dye family. These conjugates bind their target antigen in a single step, avoiding the need for a secondary reagent, and the ATTO dyes provide strong absorption, high fluorescence quantum yield, and high thermal and photostability across the visible to near-infrared spectrum.
Introduction
ATTO dyes span the ultraviolet to near-infrared range and are characterized by high molar extinction coefficients and quantum yields, with emission spectra matched to the principal output wavelengths of common flow cytometers and fluorescence microscopes. For anti-pig reagents, the most prominently documented format is PE/Atto 594, a tandem in which R-phycoerythrin serves as the 488 nm-excited donor and Atto 594 as the acceptor, yielding an excitation peak at 565 nm and an emission peak at 627 nm; it is positioned as an alternative to PE-Dazzle 594, PE-Alexa 610, PE-eFluor 610, and PE-CF594. Because the anti-pig reagent landscape is less mature than that for human or mouse targets, ATTO conjugates fill a useful niche by providing directly labeled reagents for porcine immunophenotyping.
Applications
ATTO-conjugated anti-pig primary antibodies are validated across flow cytometry, immunofluorescence, immunohistochemistry, immunocytochemistry, and Western blotting, with flow cytometry as the primary application for the PE/Atto 594 and Atto 565 formats. The 488 nm-excited PE/Atto 594 format is particularly suitable for multicolor panels because its 627 nm emission is well separated from the green FITC channel and the far-red APC channel. Direct conjugation enables single-step staining, reduces assay time, and avoids the cross-reactivity that can arise from secondary reagents, which is advantageous in porcine systems where secondary anti-pig reagents may detect endogenous immunoglobulins. The PE/Atto 594 CD3ε conjugate (clone PPT3) is documented for flow cytometry of porcine samples.
