A hapten is a small molecule that can elicit an immune response only when attached to a large carrier such as a protein; the carrier may be one that also does not elicit an immune response by itself. Haptens are involved in the production of a number of immune responses, making them a topic of interest to immunologists, and they are also used in laboratory research and some types of immunoassay and diagnostic testing.


MedKoo offers comprehensive services on hapten design and synthesis. We have extensive experience and expertise on



  • (1) select a most suitable position on a drug molecule to attach a linker, which will maximize the specificity, sensitivity and immunogenicity of the immunogen;
  • (2) perform total synthesis to make the hapten with a linker when the parent drug molecule has no suitable functional group for conjugation synthesis.
  • (3) design and synthesis of the linker with a most suitable length;
  • (4) precisely control a most suitable ratio of drug to carrier protein so as to enhance performance of the immunoassay.



Combining 20 years of experience in the development of small molecule antibodies, MedKoo holds a specific expertise in the design of small molecule / protein carrier adducts. Based on our capacities in antigen design, we offer to raise custom small molecule antibodies against a variety of targets, such as:



  • • Amino acid metabolites
  • • Lipids
  • • Saccharids
  • • Steroids
  • • Nucleotides
  • • Small molecule drugs
  • • Toxins
  • • Drug residues
  • • Pesticides residues
  • • Chemical pollutants (carcinogens, neurotoxins, endocrine disruptors)