A competitive enzyme‐linked immunosorbent assay for determination of chloramphenicol

Abstract

Chloramphenicol is a broad-spectrum antibiotic shown to have specific activity against a wide variety of organisms that are causative agents of several disease conditions in domestic animals. Chloramphenicol has been banned for use in food-producing animals for its serious adverse toxic effects in humans. Due to the harmful effects of chloramphenicol residues livestock products should be free of any traces of these residues. Several analytical methods are available for chloramphenicol analysis but sensitive methods are required in order to ensure that no traces of chloramphenicol residues are present in edible animal products. In order to prevent the illegal use of chloramphenicol, regulatory control of its residues in food of animal origin is essential. A competitive enzyme-linked immunosorbent assay for chloramphenicol has been locally developed and optimized for the detection of chloramphenicol in sheep serum. In the assay, chloramphenicol in the test samples and that in chloramphenicol-horseradish peroxidase conjugate compete for antibodies raised against the drug in camels and immobilized on a microtitre plate. Tetramethylbenzidine-hydrogen peroxide (TMB/H2O2) is used as chromogen-substrate system. The assay has a detection limit of 0.1 ng/mL of serum with a high specificity for chloramphenicol. Cross-reactivity with florfenicol, thiamphenicol, penicillin, tetracyclines and sulfamethazine was not observed. The assay was able to detect chloramphenicol concentrations in normal sheep serum for at least 1 week after intramuscular injection with the drug at a dose of 25 mg/kg body weight (b.w.). The assay can be used as a screening tool for chloramphenicol use in animals.

Sample-to-Answer Robotic ELISA

“…It is also worth noting that the LOD achieved by the Robotic ELISA system outperforms that conducted by manually operated nanofibrous membrane-based ELISA using the same colorimetric readout, which is 0.3 ng/mL . Furthermore, the LOD is comparable to the conventional microtiter plate reader-based ELISA detection …”

RepTAGs: Universal tags for isolation and labeling of proteins, for labeling live mammalian cells and for drug discovery

“…Besides applying antibiotics for the purpose of modulating the RepTAG-DNA interaction, closely monitoring a change in this interaction can, on the other hand, be applied for the detection or discovery of antibiotic substances. We applied fluorescence polarization as a fast readout system to determine the RepTAG-operator interaction in response to antibiotics contained in farming samples such as cow serum, a biologic fluid commonly used to trace antibiotics (Ambros et al, 2007;Wesongah et al, 2007) (Fig. 5A).…”

A simple and sensitive flow injection chemiluminescence immunoassay for chloramphenicol based on gold nanoparticle‐loaded enzyme

“…There are many methods for CAP detection, such as gas chromatography–mass spectrometry, 13 high performance liquid chromatography–mass spectrometry, 14 surface‐enhanced Raman scattering, 15, 16 enzyme‐linked immunosorbent assay, 17, 18 and so on 19 . Nevertheless, these methods also have some disadvantages, such as expensive instrumentation, poor selectivity, and the need for professional and labour‐intensive operation.…”