Radioligand Binding Assays

Circle Oncodesign Services

Control quality and biological activity of radioligand


As a crucial tool in characterizing the interaction between compounds and their targets, binding assays offer information-rich data to guide your discovery program. Oncodesign Services brings expertise in developing a diverse range of radioligand binding assays in various formats, ensuring your project receives a customized assay solution.

Principles of Radioligand Binding Assays


Radioligand binding assays involve using a radioactively labeled ligand, known as the radioligand, to trace and quantify its binding to the target receptor. The binding interactions can then be measured using specialized equipment that detects radioactivity.

Widely employed for characterizing drug binding to targets such as enzymes or receptors, radioligand binding assays become particularly valuable when labeling the native ligand proves challenging through alternative methods like fluorescence.

Utilizing a competition binding format, we can determine the equilibrium affinity of unlabeled compounds. Radioligand binding assays also facilitate an exploration of the binding mechanisms of drug-like molecules, and by conducting a time-course analysis, we can ascertain binding kinetics.

Different types of radioligand binding assays 


  • Competitive radioligand binding assays

    Competition-binding assays employ only a single concentration of radioligand and a competitor. Competitor can be the cold ligand or another substance which is known to have an affinity for the receptor.


    Competition assays evaluates following Binding characteristics:

    • Competition of a molecule for its target
    • Ligand recognition properties
    • Proportions of receptor subtypes in a tissue or a cell
  • Saturation radioligand binding assays

    The radioactive molecule is incubated at increasing concentrations

    • Alone: total binding (T)
    • With large excess of unradiolabled molecule: non-specific binding (NS)


    Saturation assays evaluates following Binding characteristics:

    • Specific binding
    • Kd
    • Bmax

A radionuclide full lab to support you with radioligand binding assays


With over 25 years of experience, Oncodesign Services is the best partner for your radioligand binding studies. We provide precise insights into the molecular interactions that govern the efficacy and specificity of potential therapeutic targets.

Our biochemistry and enzymology assays can include:

  • Enzymatic assay setup/design
  • Assay automation
  • Radioisotope labelling
  • Binding analysis
  • Elisa/MSD/AlphaLISA/HTRF setup and design

In combination with our medicinal chemists, in vivo pharmacologists, and DMPK scientists, our integrated teams can accelerate your research program by seamlessly integrating compound flow and knowledge.


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