Alexa Fluor conjugated primary antibody used in immunofluorescence

Most protein and cell analysis techniques involving antibodies depend upon using target-specific primary antibodies and labeled, conjugated secondary antibodies. However, using directly labeled primary antibodies enhances or simplifies certain procedures. For example, commercially available ELISA kits typically use matched pairs of target-specific (primary) antibodies in which the detector antibody of the pair is biotinylated. This arrangement enables sensitive and reliable signal generation, and amplification occurs by probing the biotin label with HRP-conjugated streptavidin. We offer many primary antibodies conjugated to different fluorescent and enzymatic labels including Alexa Fluor, HRP, and AP.

Related product and application categories

Alexa Fluor Dyes

Protein conjugates made with Alexa Fluor dyes produce fluorescence output that surpasses that of other spectrally similar fluorophore-labeled proteins.

Antibody Labeling

Can’t find a conjugated version of the primary antibody that interests you? Discover the variety of convenient and powerful options for labeling and conjugating antibodies (or other proteins) on your own.


Find a target-specific ELISA kit. Also learn about our matched antibody pairs and numerous singleplex and multiplex assays for Luminex Instruments, most of which use biotinylated detector antibodies.

Cell Analysis

Browse the many cell imaging and analysis techniques that rely on the use of primary antibodies, including those that are directly conjugated to fluors or biotin.