A new development of measurement of 19-Nortestosterone by combining immunochromatographic strip assay and ImageJ software

A rapid immunochromatographic assay was developed to detect 17-19-Nortestosterone (19-NT). The 19-NT-OVA conjugate was immobilised to nitrocellulose membrane as a test line and goat anti-rabbit IgG as a control line. Anti-19-NT polyclonal antibody labelled with colloidal gold particles acted as detector reagent. We tested the sensitivity of the strip using spiked swine urine, and analysed the intensity of test line using ImageJ software. The sensitivity by naked eye measurement was determined to be 200 ng/ml and lower limit using ImageJ was distinguished as 5 ng/ml. The total assay time was less than 20 min, suitable for screening and quantifying the residue of 19-NT in swine urine.