Development of an LED-induced Fluorescence Analysis System Using a Compact Disk-type Microfluidic Device and Its Application to Enzyme-linked Immunosorbent Assay

A novel LED-induced fluorescence analysis system using a CD-type microfluidic device was developed to miniaturize the elements of a complete analytical system. The determination of IgA in human saliva by ELISA using the developed system was evaluated. The solutions of the sample, washing reagent, enzyme-labeled anti-IgA, washing reagent and fluorescent substrate in the reservoirs on the CD-type microfluidic device were sequentially introduced into the separation and detection chamber, immobilized with an anti-IgA, by centrifugal force generated by rotation of the CD-type microfluidic device. The determination of IgA was performed by measuring the fluorescence intensity of the enzymatic product using a laboratory-made fluorescence detector with an LED and a CCD. The quantitative values of IgA obtained on the developed system were in excellent agreement with that on conventional ELISA using a 96-well microtiter plate. Since large-size and expensive peripheral equipment, such as a pump, valve, laser and microscope, are unnecessary, this system would be useful for on-site analysis, such as environmental monitoring, food safety testing and point-of-care testing.