The metabolite of nitrofurazone Monoclonal Antibody
Description
Nitrofurazone and Its Metabolite SEM
Nitrofurazone is a synthetic antibiotic banned in many countries due to its genotoxic and mutagenic risks. Its primary metabolite, SEM, is covalently bound to tissue proteins in vivo, making it stable and detectable long after the parent drug has been eliminated . SEM’s persistence poses challenges for food safety monitoring, as it can accumulate in animal-derived products like meat and eggs .
Hapten Design for SEM-Specific Antibodies
SEM, a small molecule (molecular weight <1,000 Da), lacks immunogenicity. To generate antibodies, researchers employ hapten derivatization using reagents like 2-nitrobenzaldehyde (2-NBA) or 4-carboxybenzaldehyde (4-CBA) . Derivatization enhances the molecule’s immunogenicity and allows conjugation to carrier proteins (e.g., bovine serum albumin, BSA) for immunization .
| Derivatization Reagent | Key Features | Reference |
|---|---|---|
| 2-NBA | High derivatization efficiency (>70%) | |
| 4-CBA | Enables conjugation via carboxyl groups |
Hybridoma Technology
Monoclonal antibodies are produced via hybridoma fusion of murine myeloma cells and splenocytes from immunized mice . For SEM, hapten-BSA conjugates (e.g., 2-NP-SEM) are used as immunogens. This approach yielded clones with high specificity, as demonstrated in cross-reactivity studies .
Cross-Reactivity Analysis
SEM-specific mAbs exhibit minimal cross-reactivity with other nitrofurans or metabolites, ensuring assay specificity. For example:
| Compound | IC₅₀ (ng/mL) | Cross-Reactivity (%) |
|---|---|---|
| SEM | 0.09 | 100 |
| Nitrofurazone | >1000 | <0.01 |
| Furaltadone | >1000 | <0.01 |
| AOZ (furazolidone metabolite) | >1000 | <0.01 |
Assay Performance
-
LOD (Limit of Detection): 0.09 ng/mL for SEM in spiked tissue samples .
-
Recovery: 81.1–105.3% in edible tissues, validated via LC-MS/MS .
Challenges in SEM-Based Monitoring
-
Multiple Sources of SEM: SEM is not exclusive to nitrofurazone. It occurs naturally in algae/shrimp and forms during food processing (e.g., azodicarbonamide use) .
-
Interference in Assays: High cross-reactivity with unrelated compounds (e.g., 4-CBA derivatives) necessitates rigorous antibody screening .
