Your guide to selecting an isotype control

Essentials for choosing the proper isotype control for your experiment.

Isotype controls for flow cytometry and tissue staining

​Isotype controls are important negative controls used to validate experimental results in flow cytometry and immunohistochemistry. These antibodies, having no antigen specificity, should match the clonality, isotype, and conjugation of the experimental primary antibody.

Non-specific signaling can arise both from endogenous Fc receptor binding and interaction with off-target proteins, and if the level of background is isotype-specific. Choosing the correct isotype control reduces background effects and allows interpretation of true signal. For proper interpretation of results, it is important to match the concentrations of the primary antibody and isotype control.

Isotype controls and other non-specific whole molecule immunoglobulins are also useful negative controls in immunoprecipitation experiments.

This guide will help you choose the isotype control for your experiment.

Choosing your isotype control

To choose the proper isotype control for your experiment, match the following characteristics of the primary antibody:

  1. Host species
  2. Isotype
  3. ​Conjugation format

Use the same experimental concentration of isotype control as primary antibody for proper interpretation of results.

Abcam offers a complete range of isotype controls, which are available both unconjugated and conjugated to: Alexa Fluor® dyes, HRP, Biotin, Phycoerythrin, FITC, Agarose, and other formats.

Our range of isotype controls

Use the table to select the isotype control matching your primary antibody. The product list can then be filtered using the Conjugate search filter on the left hand side of the search results.


Featured isotype controls​

AbIDDescriptionApplicationsBrand
ab172730Rabbit monoclonal, IgGICC/IF, Flow Cyt, IHC-PRabMAb®
ab171870Rabbit polyclonal, IgGWB, ChIP, IP
ab199091Rabbit monoclonal, IgG (Alexa Fluor® 488)ICC/IF, Flow Cyt

Alexa Fluor®



    Alexa Fluor® is a registered trademark of Life Technologies. Alexa Fluor®​ dye conjugates contain(s) technology licensed to Abcam by Life Technologies.
Sign up