Secondary antibodies are used for the indirect detection of target antigens. The use of  secondary antibodies requires more steps than using primary antibodies alone, but secondary antibodies can offer significant advantages such as increased sensitivity through the signal amplification, and greater flexibility in labeling and detection options.

We have developed an extensive selection of high-quality conjugated and unconjugated secondary antibodies that can be used for the fluorescent, colorimetric, and chemiluminescent detection of primary antibodies in a wide range of applications, such as cell imaging, flow cytometry and western blotting.

Included in our offering are highly cited research antibodies, many conjugated to a broad range of dyes and enzymes:

  •  Alexa Fluor® dyes
  •  Classic fluorescent dyes, such as FITC, RPE, and APC
  •  Enzyme conjugates, such as HRP and AP

Secondary antibody selection table

Reactivity Non fluorescent conjugates Fluorescent
Target Ig
NEW Superclonal™ Secondary Antibodies - A breakthrough in recombinant antibody technology designed to eliminate cross-reactivity in detection of primary antibodies

Related secondary antibodies applications

Western blot reagents and instruments, chemiluminescent, colorimetric, and fluorescent detection substrates, blocking buffers, and secondary antibody conjugates

We offer a wide selection of ELISA kits targeted to disease-related proteins for research in immunology, cancer, neurodegeneration, stem cells, and more.

Reagents and kits for cellular imaging applications such as fluorescence microscopy, IHC, ISH, HCS, LCM, and small animal in vivo imaging

Antibodies, cell functional reagents, Attune® flow cytometer, and instrument calibration products


Everyone starting out in fluorescence imaging has questions. Learn the fundamentals of fluorescence microscopy, including sample and media considerations, sample preparation, and beginner’s protocols to help you get started. We hope you will benefit from the information in Molecular Probes® School of Fluorescence.

Alexa Fluor® Labeling Kits