Fluorescent-dye conjugated secondary antibodies provide a tool for identifying proteins in many applications including fluorescent cell imaging, western blotting, immunohistochemistry and more. The advantages of using a fluorescently labeled secondary antibody include brighter signal, multiplexing capabilities, and ease of use. Browse our portfolio of Alexa Fluor secondary antibodies, classic secondaries (such as FITC and TRITC), and our selection of enzyme and biotin-labeled secondaries.

Fluorophore Reagent Selection Guide

Need to select the optimal fluorescent dyes for use with the EVOS cell imaging systems? The Fluorophore and Reagent Selection Guide for Cell Imaging is here to help!

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Quick links to secondary antibody conjugate products

Quick links to fixatives, mountants and other organelle staining reagents for use with secondary antibodies

Popular fluorescent secondary antibodies

Compare fluorophore conjugate technologies

See how classical fluorophore, Alexa Fluor, and Alexa Fluor Plus secondary antibody conjugates compare.

 Classical fluorophore conjugatesAlexa Fluor conjugatesAlexa Fluor Plus conjugates
What conjugate products are available?APC
Texas Red
Texas Red-X
Conjugates of 18 Alexa Fluor dyesConjugates of 7 Alexa Fluor Plus dyes
UseFor detection of high-abundance targets   For use with easy-to-obtain samplesFor detection of medium- to high-abundance targets   For use in most research areasFor detection of low-abundance targets   For use with hard-to-obtain samples, e.g., neuroscience 
  • Cell Imaging
    • Immunohistochemistry (IHC)
    • Immunocytochemistry (ICC)
    • Immunofluorescence (IF)
  • Multiplex, fluorescent Western blotting (WB)
Signal-to-noise ratioLowMediumHigh
PhotostabilityVarying levels of photostability, depending on dyePhotostablePhotostable
SpecificityVarious options availableVarious options availableHighly specific, low cross-reactivity (highly cross-adsorbed)
Sensitivity and brightnessLower sensitivity and brightness compared to leading Alexa Fluor conjugatesWidely recognized standard for brightness and sensitivityImproved sensitivity and brightness over leading Alexa Fluor conjugates in IF/ICC imaging and fluorescent western blotting
Range of linear detectionLowMediumHigh

Featured secondary antibody conjugate categories

Select from 18 different individual Alexa Fluor dyes and 4 Alexa Fluor tandem dyes as secondary antibody conjugates. Alexa Fluor secondary antibodies exhibit superior brightness and photostability, outperforming conventional fluorescent secondary antibodies. 

Learn about Alexa Fluor Plus secondary antibodies, which represent an advancement in fluorescent conjugate technology, designed to provide brighter signal, enhanced sensitivity, and minimal cross-reactivity in a variety of applications.

Discover features and varieties of available horseradish peroxidase (HRP), alkaline phosphatase (AP), biotin, and other enzyme or affinity-tagged secondary antibody conjugates.

Determine which Alexa Fluor secondary antibodies fit your imaging or western blotting needs by using our instrument compatibility table to guide you. Microscope, microplate reader, high-content platform and fluorescent western blotting compatibility information are also provided.

For Research Use Only. Not for use in diagnostic procedures.