ATTO-conjugated anti-rat primary antibodies are directly labeled immunoreagents in which a rat antigen-specific immunoglobulin is covalently linked to a member of the ATTO dye family. Directly ATTO-conjugated anti-rat primary antibodies, which bind a specific rat antigen and carry the dye in a single step, represent a smaller but growing category. The best-characterized example is a mouse monoclonal anti-rat Slc38a1 antibody (clone S104-32) conjugated to ATTO 488. PE-Atto 594 tandems of anti-rat CD4 are also documented.
The ATTO Dye Family and Photophysical Properties
ATTO dyes span the ultraviolet to near-infrared spectrum. Their defining characteristics are strong absorption, high fluorescence quantum yield, high thermal and photostability, and excellent water solubility. ATTO 488, for example, exhibits very little triplet formation and is optimally excited by the 488 nm argon-ion laser line, with an absorption maximum around 502–508 nm. ATTO 590, a rhodamine-class dye, has an absorption maximum of 593 nm,
