For the best experience on the Abcam website please upgrade to a modern browser such as Google Chrome

Hello. We're improving abcam.com and we'd welcome your feedback.

Hello. We're improving abcam.com and we'd welcome your feedback.

Infomation icon

We haven't added this to the BETA yet

New BETA website

New BETA website

Hello. We're improving abcam.com and we'd welcome your feedback.

Take a look at our BETA site and see what we’ve done so far.

Switch on our new BETA site

Now available

Search and browse selected products

  • A selection of primary antibodies

Purchase these through your usual distributor

In the coming months

  • Additional product types
  • Supporting content
  • Sign in to your account
  • Purchase online
United States
Your country/region is currently set to:

If incorrect, please enter your country/region into the box below, to view site information related to your country/region.

Call (888) 77-ABCAM (22226) or contact us
Need help? Contact us

  • My account
  • Sign out
Sign in or Register with us

Welcome

Sign in or

Don't have an account?

Register with us
My basket
Quick order
Abcam homepage

  • Research Products
    By product type
    Primary antibodies
    Secondary antibodies
    ELISA and Matched Antibody Pair Kits
    Cell and tissue imaging tools
    Cellular and biochemical assays
    Proteins and Peptides
    By product type
    Proteomics tools
    Agonists, activators, antagonists and inhibitors
    Cell lines and Lysates
    Multiplex miRNA assays
    Multiplex Assays
    By research area
    Cancer
    Cardiovascular
    Cell Biology
    Epigenetics
    Metabolism
    Developmental Biology
    By research area
    Immunology
    Microbiology
    Neuroscience
    Signal Transduction
    Stem Cells
  • Customized Products & Partnerships
    Customized Products & Partnerships

    Customized products and commercial partnerships to accelerate your diagnostic and therapeutic programs.

    Customized products

    Partner with us

  • Support
    Support hub

    Access advice and support for any research roadblock

    View support hub

    Protocols

    Your experiments laid out step by step

    View protocols

  • Events
    • Conference calendar
    • Cancer
    • Cardiovascular
    • Epigenetics & Nuclear signaling
    • Immunology
    • Neuroscience
    • Stem cells
    • Tradeshows
    • Scientific webinars
    Keep up to date with the latest events

    Full event breakdown with abstracts, speakers, registration and more

    View global event calendar

  • Pathways
    Cell signalling pathways

    View all pathways

    View all interactive pathways

How to choose an isotype control antibody

Related

  • View all isotype controls
    • Isotype controls validated for flow cyt
    • Primary antibodies
      • Primary antibodies validated for flow cyt
        • Primary antibodies validated for IHC
          • Recombinant antibodies
            • See the data for yourself
            • Directly conjugated antibodies
              • Select and compare conjugated antibodies for flow cyt
              • Carrier-free antibodies
                • Trial-size antibodies
                  • Antibody structure and isotypes
                    • Flow cytometry resources
                      • Recommended controls
                        • Introduction to flow cytometry
                          • Troubleshooting
                            • Training: flow cytometry
                              • IP protocol
                                • The complete IHC guide

                                  Your guide to selecting the right isotype control for your experiment.

                                  Updated October 18, 2022

                                  Contents

                                  • How to choose isotype controls
                                  • Different types of isotype controls
                                  • Popular isotype control products
                                  An isotype control is an antibody selected as a negative control for flow cytometry experiments, and is used to detect non-specific binding. Isotype controls can be conjugated or unconjugated, and should match the host species, the Ig subclass, and conjugation of the primary antibody used against the target of interest. For example, a rabbit monoclonal to CD4 FITC-conjugated should be matched with a rabbit IgG isotype control FITC-conjugated.
                                  An isotype control will determine the presence and extent of non-specific antibody binding, which arises when an antibody binds to endogenous Fc receptors or interacts with off-target proteins and molecules. Choosing the correct isotype control for your experimental conditions is crucial to distinguishing the true antibody signal from non-specific background staining, as well as to limit off-target interactions with dyes or enzymes conjugated to the antibody. 

                                  An isotype control is an antibody selected as a negative control for flow cytometry experiments and is used to detect non-specific binding. Isotype controls can be conjugated or unconjugated and should match the host species, the Ig subclass, and the conjugation of the primary antibody used against the target of interest. For example, a rabbit monoclonal to CD4 FITC-conjugated should be matched with a rabbit IgG isotype control FITC-conjugated.

                                  An isotype control will determine the presence and extent of non-specific antibody binding, which arises when an antibody binds to endogenous Fc receptors or interacts with off-target proteins and molecules. Choosing the correct isotype control for your experimental conditions is crucial to distinguishing the true antibody signal from non-specific background staining, as well as to limit off-target interactions with dyes or enzymes conjugated to the antibody. 

                                  Browse our total range of isotype controls

                                  How to choose your isotype control

                                  Optional: Make sure isotype controls are suitable for your experiment

                                  Isotype controls are suitable for many applications either as a negative control (Flow cyt, imaging) or as a standard blocking and protein coating agent (IF, IHC, WB, ELISA). As isotype controls were developed for surface staining, they generally do not work well with intracellular staining. Most importantly, these controls should not be used to differentiate positive and negative cells or to set positive gating regions.

                                  1: Choose an isotype control that does not recognize your target antibody.

                                  To effectively determine non-specific binding, isotype control antibodies must be specific to a target, which is not present in your sample. 

                                  2: Choose an isotype control raised in the same host species as your target antibody

                                  Both the host and class of the isotype control antibody impact how it interacts with Fc and other cell components in your sample.

                                  3: Choose an isotype control that matches the class and sub-class of your primary antibody.

                                  As the five different heavy chain classes (also known as isotypes) have different functions and locations, it’s important your isotype control antibody matches that of your primary antibody. While class and sub-class may not need to be matched for isotype controls used in western blot or IP, this is important in flow cytometry and double-labeling experiments.

                                  You can find the isotype of all primary antibodies under the ‘Properties’ section on our datasheets.  

                                  Check the class and sub-class of our isotype controls in the table below.

                                  4: If using a conjugated primary antibody, an isotype control should match the conjugation format

                                  Isotype controls can be unconjugated or conjugated across various formats eg Alexa Fluor® dyes, PE, APC, HRP, biotin or FITC.

                                  Optional: Minimize experimental differences

                                  To keep your primary and isotype control antibodies as similar as possible, try to match:
                                  • Manufacturing process – primary and isotype control antibodies from the same supplier tend to work best together.
                                  • Clonality –  whether your primary antibody is polyclonal or monoclonal, make sure your isotype control has the same clonality.
                                  • Format and purity – both can vary depending on supplier or intended use for the antibody. What the exact purity and format of your primary is not important, just make sure the isotype control matches it.
                                  • Volume - if using test antibodies, identify the microgram quantity of the antibody at that volume and get an equal mass of isotype control.
                                  • Concentration – like format and purity, concentration can vary across different antibodies and suppliers. If you have optimized your primary antibody dilution, do the same for your isotype control.
                                  • Storage and handling conditions - if using a secondary antibody, add the isotype control in the same way as your primary antibody.
                                  All our primary antibody datasheets include concentration, purity, clonality and formulation details under the ‘Properties’section.

                                  ​

                                  Different types of isotype controls

                                  There are five main mammalian antibody isotypes: IgA, IgD, IgE, IgG, and IgM. IgG isotypes can also be further divided based on light chains. Different species have different sets of isotypes, for example, rabbits have more IgG while mice have more IgM. IgG isotypes are more specific, so antibodies produced in rabbits have higher specificity and affinity.

                                  Use the table and links to select the isotype control matching your primary antibody. You can then filter product lists using the 'Conjugate' search filter on the left-hand sidebar to find products that match your conjugate.




                                  IgG


                                  IgM

                                  IgG

                                  IgG1

                                  IgG2aIgG2bIgG2cIgG3IgM

                                  Mouse

                                  XXXXXXX

                                  Rat

                                  XXXXX
                                  X
                                  RabbitX




                                  X
                                  HamsterX




                                  X

                                  Mouse IgA | Mouse IgE| Goat IgG | Sheep IgG | Chicken IgY

                                  Browse our total range of isotype controls


                                  Our most popular isotype controls​

                                  Isotype controls, unconjugated

                                  NameApplicationsReferences
                                  Recombinant Rabbit IgG, monoclonal [EPR25A] (ab172730)ICC/IF, Flow Cyt, IHC-P301
                                  Rabbit IgG, polyclonal (ab171870)WB, ChIP, IP196
                                  Mouse IgG1, kappa monoclonal [15-6E10A7] (ab170190) Flow Cyt, ICC, IHC-P

                                  17

                                  Mouse IgG2a, Kappa Monoclonal [MOPC-173] (ab18413)Flow Cyt, IP, WB, IHC-Fr, IHC-P, ChIP55
                                  Mouse IgG2b, kappa monoclonal [7E10G10] (ab170192)Flow Cyt, ICC/IF3
                                  Rat IgG2a, kappa monoclonal [RTK2758] (ab18450)Flow Cyt, ICC/IF, IP, WB, IHC-P, IHC-Fr12
                                  Rat IgG1, kappa monoclonal [RTK2071] (ab18412)Flow Cyt3

                                  Rabbit isotype controls, conjugated

                                  NameApplicationsReferences
                                  Alexa Fluor® 488 Rabbit IgG, monoclonal [EPR25A] (ab199091)ICC/IF, Flow Cyt15
                                  Alexa Fluor® 647 Rabbit IgG, monoclonal [EPR25A] (ab199093)ICC/IF, Flow Cyt13
                                  PE Rabbit IgG, monoclonal [EPR25A] (ab209478)ICC/IF, Flow Cyt2
                                  APC Rabbit IgG, monoclonal [EPR25A] (ab232814)Flow Cyt1

                                  Mouse isotype controls, conjugated

                                  NameValidated inReferences
                                  PE Mouse IgG1 [B11/6] (ab91357)Flow Cyt5
                                  FITC Mouse IgG1 [B11/6] (ab91356)Flow Cyt9
                                  FITC Mouse IgG2a, monoclonal (ab81197)Flow Cyt4

                                  Rat isotype controls, conjugated

                                  NameValidated inReferences
                                  FITC Rat IgG1, kappa [RTK2071] (ab18404)Flow Cyt
                                  FITC Rat IgG2a, kappa [RTK2758] (ab18446)Flow Cyt
                                  FITC Rat IgG2b, kappa [eB149/10H5] (ab136125)Flow Cyt, ICC/IF

                                  Browse our total range of isotype controls


                                    Alexa Fluor® is a registered trademark of Life Technologies. Alexa Fluor®​ dye conjugates contain(s) technology licensed to Abcam by Life Technologies.
                                  Get resources and offers direct to your inbox Sign up
                                  A-Z by research area
                                  • Cancer
                                  • Cardiovascular
                                  • Cell biology
                                  • Developmental biology
                                  • Epigenetics & Nuclear signaling
                                  • Immunology
                                  • Metabolism
                                  • Microbiology
                                  • Neuroscience
                                  • Signal transduction
                                  • Stem cells
                                  A-Z by product type
                                  • Primary antibodies
                                  • Secondary antibodies
                                  • Biochemicals
                                  • Isotype controls
                                  • Flow cytometry multi-color selector
                                  • Kits
                                  • Loading controls
                                  • Lysates
                                  • Peptides
                                  • Proteins
                                  • Slides
                                  • Tags and cell markers
                                  • Tools & Reagents
                                  Help & support
                                  • Support
                                  • Make an Inquiry
                                  • Protocols & troubleshooting
                                  • Placing an order
                                  • RabMAb products
                                  • Biochemical product FAQs
                                  • Training
                                  • Browse by Target
                                  Company
                                  • Corporate site
                                  • Investor relations
                                  • Company news
                                  • Careers
                                  • About us
                                  • Blog
                                  Events
                                  • Tradeshows
                                  • Conferences
                                  International websites
                                  • abcam.cn
                                  • abcam.co.jp

                                  Join with us

                                  • LinkedIn
                                  • facebook
                                  • Twitter
                                  • YouTube
                                  • Terms of sale
                                  • Website terms of use
                                  • Cookie policy
                                  • Privacy policy
                                  • Legal
                                  • Modern slavery statement
                                  © 1998-2023 Abcam plc. All rights reserved.