Corticosteroids EIA

Cat. No.: 5081COR1p



Synthetic corticosteroids are widely used in live-stock breeding to treat inflammatory diseases. The Maximum Residue Limits (MRLs) for dexamethasone and betamethasone in milk, tissue, kidney and liver are 0.3, 0.75, 0.75 and 2.0 µg/kg, respectively. For prednisolone the MRLs are 4, 4, 6, 10 and 10 µg/kg for muscle, fat, milk, liver and kidney, respectively. For methylprednisolone the MRLs are 10 µg/kg for each of the matrices mentioned. Some corticosteroids are permitted for use as a drug. However, corticosteroids in general might also be used as growth promoter in meat production. In all European Community countries the use of growth promoters has been banned since 1986. The generic Corticosteroid-EIA is a competitive enzyme immunoassay for the screening of feed, milk and urine for the presence of the following corticoste­roids (% of cross-reactivity): flumethasone (125%), dexamethasone (100%), betametha­sone (93%), triamcinolone (33%), prednisolone (21%), dianabol (7.5%) and methylprednisolone (2.8%). The dose-response curve shows a measu­ring range for dexamethasone of 0.125-4 ng/ml. Milk can be used directly in this test with a sensitivity down to 0.15 ng/ml. For feed samples, extraction methods are described in the manual and sensitivities down to 20 ng/g can be obtained. Urine samples can be applied after a dilution in buffer or after an HPLC fractionati­on. Tissue samples need a three phase extraction and a further clean-up procedure.