Development of an indirect competitive immunochromatographic strip test for rapid detection and determination of anticancer drug, harringtonine

Harringtonine (HT) is a natural compound, which is mainly produced by the genus Cephalotaxus, and has been clinically utilized in China for the treatment of acute leukemia and lymphoma. However, the amounts of HT in the Cephalotaxus species are very small; therefore, plant tissue cultures have been focused upon to enhance HT production. Qualitative/quantitative methods for HT detection are required to screen superior cell lines. We developed a one-step indirect competitive immunochromatographic assay (ICA) using colloidal gold nanoparticles conjugated with highly specific monoclonal antibodies against HT (MAb 1D2) for simple, rapid, and sensitive detection of HT in plant samples. This ICA can be completed in 15 min after dipping the strip into analytes with a limit of detection of ∼313 ng/mL. In developed ICA, fiber pad which is usually used for conventional ICA, was not used to shorten the time for preparing chromatographic strip, resulting in a decrease in the volume of valuable analytes (20 μL). Considering simplicity, rapidity, and sensitivity of the developed ICA, this study could be applied to a fieldwork study for finding new natural resources containing HT.