Skin Rashes Research Today is a free monthly online journal that collates and summarizes the latest research about Skin Rashes, including details on dermatitis, itches, creams, medication, treatment.

On-chip micro-flow polystyrene bead-based immunoassay for quantitative detection of tacrolimus (FK506).

Murakami Y, Endo T, Yamamura S, Nagatani N, Takamura Y, Tamiya E

Department of Chemical Materials Science, School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Nomigun, Ishikawa 923-1292, Japan. murakami@mpcrf.or.jp

Tacrolimus (FK506) is a widely used immunosuppressant for preventing allograft rejection and the treatment of atopic dermatitis. FK506 necessitates therapeutic drug monitoring because of inter- and intrapatient variability and the lack of correlation between the administered dose and the blood concentration. Previous immunoassay-based methods required a relatively long assay time and troublesome liquid-handling procedures. In the present study, we aimed to establish a rapid monitoring method for FK506 determination by using a poly(dimethylsiloxane) (PDMS)-based microfluidic device. Polystyrene beads were coated with mouse anti-FK506 antibody and placed in the flow channel. As a competitive assay, sample solution was allowed to react in the flow channel. After the addition of the fluorogenic substrate, the fluorescent signal was observed under a microscope. As a result, the developed assay allowed a short detection time of approximately 15 min per each sample and a high sensitivity even by using only a single bead. The feasibility of performing a competitive assay using a PDMS-based antibody chip gives promising results over the existing immunoassay-based methods.

Published 6 October 2004 in Anal Biochem, 334(1): 111-6.
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