마이크로비드를 이용한 미세 유체 채널내의 B형 간염 바이러스 측정

Abstract

Microfluidic devices have been developed rapidly in medical analysis, environmental monitoring, biochemical analysis, and microchemistry. These devices provide various advantages over bench-top instruments. They include smaller dead volume and sample consumption, shorter analysis time, lower cost, greater portability, and high-throughput. Conventional immunoassay is important analytical methods for clinical diagnoses and biochemical studies. However, it takes relatively longer experimental time, troublesome procedures, and expensive reagents. In this paper, we propose a sandwich immunoassay system with microfluidic channel that enables the detection of Hepatitis B viral antigen using microbeads. The device was fabricated from poly (dimethylsiloxane) (PDMS) using standard photolithographic and replica molding methods. The microfluidic chip consists of three channel systems with inlet channel, filter chamber, and outlet channel. HBV monoclonal antibody (ag1) labeled with biotin were immobilized onto microbeads coated with streptavidin. The modified microbeads were packed in the microchannel, and then HBs antigen (625 ng/ml) was loaded through the inlet channel at a flow rate of 6.7 ㎕/min. Fluorescein isothiocyanate (FITC) labeled HBV monoclonal antibody (ag8) was used to detect HBs antigen. After Biotin-Ab (ag1)-HBs antigen-Ab (ag8)-FITC complex was formed within microchannel, fluorescence intensity was monitored with fluorescence microscope. In this research, the immunoreaction was detected within 30 min using 100 ㎕ of sample. It is our goal to develop a complete immunoassay system using microfluidic device that will be able to efficiently detect a wide range of different viral antigen present in very minute amounts.