We have been working on the development of capillary-assembled microchip (CAs-CHIP), which allowed multi-analyte detection by using different chemically-modified square capillaries embedded into PDMS microchannels [Anal.Chem., 2004, 76, 3222.].Among these works, we recently developed reagent-release capillary (RRC) which releases the analytical reagents from capillary wall upon introduction of sample solution by capillary action, and the released reagents react with sample to give fluorescence response.This technique allowed the development of very simple and disposable multianalyte sensing device for use in bioanalyses by simply embedding various RRCs into PDMS microchannels.