Tetracyclines immunoassay

Several qualitative and quantitative immunochemical methods for CAP analysis in biological matrices of animal origin have been described [101,102, 104,105] (see Table 3). Van de Water et al. [ 102] described an ELISA that detected CAP in swine muscle tissue with an IC50 value of 3 ng mL1. This immunoassay was improved and subsequently optimized incorporating the streptavidin-biotin amplification system. There are also several commercially available test kits (see Table 4). RIDASCREEN is a competitive enzyme immunoassay for the quantitative analysis of CAP residues in milk, eggs, and meat in a microtiter plate. The measurement is made photometrically, obtaining a LOD of 100 ng L 1 in meat and eggs and 150 ng L 1 in milk. The test has been also applied to the analysis of tetracyclines. 

Immunochemical methods have been developed and placed on the market to analyze tetracycline residues (see Table 4). Thus, a qualitative EIA has been developed and used to analyze tetracyclines in honey samples with a detection level of 20 pg/kg-1 [96]. A microplate-based indirect ELISA has been developed to analyze tetracyclines using polyclonal antibodies. The assay could measure tetracycline in the range between 0.1 and 6 ng mL L Other tetracycline antibiotics such as chlortetracycline, rolitetracycline, or minocycline are also highly recognized in this assay [98]. Several immunoassay kits are commercially available for the analysis of tetracyclines although, to our knowledge, none of them... 

As occurred with the other antibiotics, commercial immunoassay formats, also available as kits for tetracyclines and penicillins such as the Parallux, the LacTek, or the Charm II, have also been placed on the market for the analysis of sulfonamides (see Table 4). Thus, the Parallux detects sulfamethazine and sulfadimethoxine in raw milk with a LOD of 10 pg L1. The Charm II detects almost all sulfonamides in honey and milk with a LOD in the range from 1 to 10 pg L, whereas LacTek is able to detect sulfamethazine. Moreover, the 5101SULlp and 5101SUDAlp tests reach LOD values for sulfamethazine and sulfadiazine of around 0.2 pg L 1 and they have been applied to the analysis of urine, milk, and plasma. These tests have proved to be efficient as a point of care for on-site applications on farms. Moreover, commercially available antibodies can be found from several sources such as Silver Lake Research, US Biological, Cortex Biochem. Inc., Accurate Chemical Scientific, Fitzgerald Industries International Inc., and Biotrend Chemikalien GmbH. 

We have found only one attempt to use immunoassays to detect sulfonamides in environmental samples. As in the case of penicillins and tetracyclines and also for fluoroquinolones (see below), Campagnolo et al. [84] measured sulfonamides in water samples proximal to a farm in Iowa using a commercial Charm II RIA test, accomplishing a LOD of 5 pg L 1 for sulfamethazine. 

Pastor-Navarro, N., S. Morais, A. Maquieira, et al. 2007. Synthesis of haptens and development of a sensitive immunoassay for tetracycline residues Application to honey samples. Anal. Chim. Acta 594 211-218. 

In summary, rapid tests, either immunoassay or enzymatic formats, are the methods of choice when qualitative or semi-quantitative results are required within a short timescale, specifically, around 30 min for targeted residue screening. In general, these assay formats are portable (suitable for in situ testing) and simple to both operate and interpret. A wide variety of test formats are commercially available, many of which are applicable for the detection of classes of antibiotics, such as P-lactams and tetracyclines with detection capabilities at or below the appropriate RLs. As with other test kits, it is important to determine the applicability of the assay for the specific matrix type prior to use as certain matrices are known to contain interference that causes elevated false non-compliant/compliant rates. 

Prostaglandin E2 (PGE2) Immunoassay. Parental PC-3 cells and the PC-3 tetracycline-inducible COX-2 antisense clones with or without doxycycline (2 p.g/mL) pretreatment were propagated to 1 x 10 cells in T-75 flasks in 10% FBS-supple-... 

A commercially available RIA developed as a screen for tetracycline antibiotics in serum, urine, milk, and tissue of livestock has been adapted by Meyer and co-workers to analyze water samples. The interest in pharmaceutical compounds in the enviromnent is relatively new. Immunoassays for pharmaceutical compounds are commonly used in biological media where the concentrations are quite high. Therefore, in this RIA the lower limit of antibiotic detection had to be modified to enable quantification of antibiotic levels as low as one part per billion in water samples. 

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