RESUMO
Background: Dexamethasone is a synthetic corticosteroid similar to cortisol produced naturally by the adrenal glands. As an anti- inflammatory and immunosuppressive agent, it is used in many diseases such as rheumatoid arthritis and allergic anaphylactic shock, and its suppression test to diagnose Cushing's syndrome. Its further use includes its administration before antibiotics in bacterial meningitis, antitumor treatment, for treatment of glucocorticoid resistance, Addison抯 disease, and congenital adrenal hyperplasia. The drug is abused by using it in animal husbandry as a growth promoter and in horse sports to enhance their performance. Methods: In this study, the development of homologous ELISA using Dexamethasone-21-hemisuccinate (DEX-21-HS)-Bovine serum albumin antiserum and Dexamethasone-21-hemisuccinate (DEX-21-HS)-Horseradish peroxidase enzyme conjugate has been done. The n-hydroxysuccinimide ester method was used to prepare the immunogen and enzyme conjugate. Results: The sensitivity 0.25 ng/mL, affinity 2.8x10-8 L/mol and ED50 4.98 ng/mL of the assay were found. The cross-reactivity of the assay was checked and found with three steroids (Corticosterone- 1.13%, Progesterone- 2.25% and Prednisolone- 6.3%) out of 48 structurally related steroids. Then, analytical variables of the developed assay were studied, such as recovery (98.55% to 105.08%), precision (Inter and Intra- assay coefficient of variation <9.28%), correlation (R2= 0.98) by utilizing a commercially available Dexamethasone kit for comparison. Conclusion: This study concluded that low-cost indigenous ELISA for Dexamethasone had been developed, which can give results within 75-80 minutes.