Design and Synthesis of Haptens for Semicarbazide (SEM)

As an expert in the field of antibody discovery, Creative Biolabs is helping our customers with various small molecule antibody discovery services targeting semicarbazide (SEM). Besides, based on our deep analytical capabilities and vast experience in hapten studies, our client-focused, integrated team will anticipate challenges, overcome difficulties and provide custom hapten design and synthesis solutions with numerous assays. We guarantee the finest results for our customers all over the world.

Introduction to Semicarbazide (SEM)

Nitrofurazone is a cheap and effective antibiotic that has been broadly used for the prevention and treatment of infectious diseases caused by bacteria and protozoa. However, pilot studies have demonstrated that nitrofurazone can lead to harmful effects on humans and then it has been banned in many countries. Semicarbazide (SEM), is a key nitrofurazone metabolite that can bind with specific proteins to form a stable structure. Thus, SEM has become a perfect marker for measuring the illegal use of nitrofurazone in animal food production. Nowadays, a number of analytical methods, such as immunosorbent assay (IA), the enzyme-linked immunosorbent assay (ELISA), liquid chromatography-mass spectrometry (LC-MS), as well as ultraviolet (UV) and diode array detector assay, have been developed for detecting the presence of SEM in animal tissues. Moreover, recent researchers have demonstrated that several small-molecule antibodies against SEM have been generated for developing novel screening system for SEM. For instance, a new monoclonal antibody (McAb) against SEM derivatives has been exclusively reported. The data have suggested that this antibody has a high specificity and sensitivity against SEM and has no cross-reaction with other nitrofuran metabolites.

Chemical structures of nitrofurazone, SEM, and the cross-linking hapten CPSEM. Fig.1 Chemical structures of nitrofurazone, SEM, and the cross-linking hapten CPSEM. (Gao, 2007)

Our Platform for Design and Synthesis of SEM Haptens

SEM contamination has aroused much attention in the past few years due to the potential risk to human health. A number of strategies have been used for monitoring SEM in animal tissue samples. Among them, small-molecule antibodies against SEM derivatives have become a powerful tool for developing new effective immunoassays for detecting SEM in the animal food industry. Currently, Creative Biolabs provides a wide spectrum of SEM-based hapten discovery services for our worldwide customers. In general, haptens for SEM will be designed by derivatizing SEM with 3-carboxybenzaldehyde (3-CBA) or 4-carboxybenzaldehyde (4-CBA). The carboxyphenyl derivatives (CPSEM) of SEM will be further conjugated to a carrier protein to produce coating antigens. Afterward, a group of animals, including rats and mice, will be immunized to produce specific antibodies based on the hybridoma technique. The positive hybridomas will be selected by using different ELISA assays. Furthermore, the antibodies specific to SEM will be subcloned and cultured into a new plate. Additionally, we also provide a range of antibody assessment services, to evaluate the sensitivity, cross-reactivity, and efficacy of candidate antibodies in practical use.

Negative hydronium mass spectra of CPSEM. Fig.2 Negative hydronium mass spectra of CPSEM. (Gao, 2007)

Creative Biolabs is dedicated to expanding cutting edge hapten discovery across a range of applications. With our proven competencies and regulatory expertise, we are therefore confident in offering the best services targeting SEM. We can provide many flexible options, from which you can always find a better match for your particular project. If you are interested in our services, please contact us for more details.


  1. Gao, A.; et al. Preparation of monoclonal antibodies against a derivative of semicarbazide as a metabolic target of nitrofurazone. Analytica Chimica Acta. 2007, 592(1): 58-63.
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