Microfluidic devices and observation methods

Abstract

A microfluidic device includes a substrate having an electromagnetic wave transmission property, a micropore array layer formed on the substrate and having microwells such that the microwells is configured to receive a target of analysis, and a light absorption layer formed over the microwells of the micropore array layer such that the light absorption layer absorbs an electromagnetic wave.

What is claimed is: 
     
         1 . A microfluidic device, comprising:
 a substrate having an electromagnetic wave transmission property;   a micropore array layer formed on the substrate and having a plurality of microwells such that the plurality of microwells is configured to receive a target of analysis; and   a light absorption layer formed over the plurality of microwells of the micropore array layer such that the light absorption layer absorbs an electromagnetic wave.   
     
     
         2 . The microfluidic device of  claim 1 , wherein the light absorption layer includes a light absorption material that absorbs light of a wavelength in accordance with the target of analysis. 
     
     
         3 . The microfluidic device of  claim 1 , wherein the light absorption layer is liquid. 
     
     
         4 . The microfluidic device of  claim 2 , wherein the light absorption layer is liquid. 
     
     
         5 . The microfluidic device of  claim 3 , wherein the liquid is not readily miscible with an aqueous liquid to be introduced into the microwells of the micropore array layer. 
     
     
         6 . The microfluidic device of  claim 4 , wherein the liquid is not readily miscible with an aqueous liquid to be introduced into the microwells of the micropore array layer. 
     
     
         7 . The microfluidic device of  claim 1 , wherein the light absorption layer includes a colored component. 
     
     
         8 . A fluorescence observation kit, comprising:
 the microfluidic device of  claim 1 .   
     
     
         9 . A method of detecting a target of analysis, comprising:
 introducing an aqueous liquid including the target of analysis into the plurality of microwells of the micropore array layer in the microfluidic device of  claim 1 ;   forming the light absorption layer on the aqueous liquid introduced into the microwells of the micropore array layer such that the aqueous liquid is sealed in the microwells of the micropore array layer;   irradiating a first electromagnetic wave onto the microwells of the micropore array layer; and   detecting a second electromagnetic wave emitted from the microwells of the micropore array layer.   
     
     
         10 . The method of  claim 9 , wherein the detecting is conducted through an outer surface of the substrate after the irradiating of the first electromagnetic wave. 
     
     
         11 . The method of  claim 10 , wherein the detecting is conducted on an observation surface located inside the microwells of the micropore array layer, which is in contact with the light absorption layer. 
     
     
         12 . The method of  claim 10 , wherein the detecting is conducted on an observation surface located inside the microwells of the micropore array layer, and the light absorption layer is located farther from the observation surface. 
     
     
         13 . The method of  claim 11 , wherein the target of analysis is one of DNA, RNA, miRNA, mRNA, and protein. 
     
     
         14 . The method of  claim 12 , wherein the target of analysis is one of DNA, RNA, miRNA, mRNA, and protein. 
     
     
         15 . The method of  claim 11 , wherein the detecting comprises detecting a signal from an enzymatic reaction when the enzymatic reaction occurs in the aqueous liquid applied on the observation surface. 
     
     
         16 . The method of  claim 12 , wherein the detecting comprises detecting a signal from an enzymatic reaction when the enzymatic reaction occurs in the aqueous liquid applied on the observation surface. 
     
     
         17 . The method of  claim 15 , wherein the target of analysis is nucleic acid, and the enzymatic reaction is an Invader reaction. 
     
     
         18 . The microfluidic device of  claim 1 , wherein the liquid of the light absorption layer comprises a sealant and a light absorbent substance soluble in the sealant. 
     
     
         19 . The microfluidic device of  claim 1 , wherein the micropore array layer is integrally molded with the substrate. 
     
     
         20 . The microfluidic device of  claim 1 , wherein the light absorption layer includes a colored component comprising a pigment such that the pigment has a grain size of not more than one-fifth of a dimension of an opening of each of the microwells in a radial direction.