HOLUBOVÁ Barbora author GÖSELOVÁ Sandra author ŠEVČÍKOVÁ Ludmila author VLACH Miroslav author BLAŽKOVÁ Martina author LAPČÍK Oldřich author FUKAL Ladislav author text journal article 2013 An enzyme immunoassay (ELISA) and an immunochromatographic strip were designed for a rapid detection of nortestosterone in dietary supplements. Two polyclonal antibodies and two types of nortestosterone-protein coating conjugates were tested to develop the most appropriate method. Under optimal experimental conditions, the most sensitive ELISA achieved the IC₅₀and the limit of detection values of 6.41 and 0.09 ng/ml, respectively. The assay specificity was tested measuring cross-reactivity of several steroids. The interference with the assay was negligible (< 0.1%), except for cross-reactivity with another frequently abused steroid testosterone (23%). The optimised gold particle-based immunochromatographic strip provided in semi-quantitative test a visual detection limit of 1 ng/ml. None of these methods showed the interference using a filtrate of the suspension of non-contaminated sample. After the validation for particular matrices, the ELISA and the strip test could be useful tools for a rapid analysis of nortestosterone in crude extracts of dietary supplements. 19-nortestosterone; ELISA; colloidal gold immunoassay; strip test 10.17221/507/2012-CJFS https://cjfs.agriculturejournals.cz/artkey/cjf-201305-0013.php https://cjfs.agriculturejournals.cz/artkey/cjf-201305-0013.php continuing 31 5 514 519 2013 12121800 periodical academic journal