Method of measuring quantity of substrate

Abstract

A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltage to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction, and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.

1 - 33 . (canceled) 
     
     
         34 . A method of measuring a quantity of a substrate using a biosensor, the method comprising:
 providing a biosensor which includes:
 an insulating board; 
 a sample supplying path provided on the insulating board; 
 a first pair of electrodes and a second pair of electrodes provided on the insulating board in order from a first opening of the sample supplying path to a second opening of the sample supplying path; and 
 a reagent layer provided on at least the sample supplying path; and 
   performing a measuring process when, after a sample liquid is applied to the second opening of the sample supplying path, a first voltage measured using the second pair of electrodes becomes equal to or greater than a first predetermined value and a second voltage measured using the first pair of electrodes becomes equal to or greater than a second predetermined value.   
     
     
         35 . The method of  claim 34 , wherein the reagent layer is provided on at least the first pair of electrodes. 
     
     
         36 . The method of  claim 34 , wherein the measuring process is not performed when the first voltage is less than the second predetermined value. 
     
     
         37 . A method of measuring a quantity of a substrate using a biosensor, the method comprising:
 providing a biosensor which includes:
 an insulating board; 
 a sample supplying path provided on the insulting board; 
 a first pair of electrodes and a second pair of electrodes provided on the insulating board in order from a sample liquid applying part of the sample supplying path to an air hole of the sample supplying path; and 
 a reagent layer provided on at least the sample supplying path; and 
   performing a measuring process when, after a sample liquid is applied to the air hole, a first voltage measured using the second pair of electrodes becomes equal to or greater than a first predetermined value and a second voltage measured using the first pair of electrodes becomes equal to or greater than a second predetermined value.   
     
     
         38 . The method of  claim 37 , wherein the reagent layer is provided on at least the first pair of electrodes. 
     
     
         39 . The method of  claim 37 , wherein the measuring process is not performed when the first voltage is less than the second predetermined value. 
     
     
         40 . A method of measuring a quantity of a substrate in a sample liquid, the method comprising the steps of:
 providing a biosensor which includes:
 a sample supplying path by which the sample liquid is supplied to the biosensor through a first opening; 
 a first pair of electrodes located at least in part in the sample supplying path; 
 a second pair of electrodes provided downstream of the first pair of electrodes along the sample supplying path in the direction of flow of the sample liquid and between the first pair of electrodes and a second opening that is in communication with the sample supplying path; and 
   determining whether a first voltage measured between the second pair of electrodes becomes equal to or greater than a first predetermined value and determining whether a second voltage measured between the first pair of electrodes becomes equal to or greater than a second predetermined value, thereby determining whether the sample liquid was applied to the second opening instead of to the first opening.   
     
     
         41 . The method of  claim 40 , wherein the quantity of the substrate is not measured if the determining step determines that the sample liquid was applied to the second opening. 
     
     
         42 . The method of  claim 40 , wherein the second opening comprises an air hole. 
     
     
         43 . The method of  claim 40 , wherein the quantity of the substrate is not measured if the second voltage is less than the second predetermined value. 
     
     
         44 . The method of  claim 40 , wherein the reagent layer is provided on at least the first pair of electrodes. 
     
     
         45 . A method of measuring a quantity of a substrate in a sample liquid, the method comprising:
 providing a biosensor which includes:
 a sample supplying path by which the sample liquid is supplied to the biosensor from a sample inlet; 
 a first pair of electrodes located at least in part in the sample supplying path; and 
 a second pair of electrodes provided downstream of the first pair of electrodes along the sample supplying path in the direction of flow of the sample liquid and between the first pair of electrodes and an air hole that is in communication with the sample supplying path; and 
   measuring a first voltage between the second pair of electrodes and a second voltage between the first pair of electrodes to determine whether the sample liquid was applied to the air hole instead of to the sample inlet.   
     
     
         46 . The method of  claim 45 , further comprising the step of measuring the quantity of the substrate if the first voltage becomes equal to or greater than a first predetermined value and the second voltage becomes equal to or greater than a second predetermined value. 
     
     
         47 . The method of  claim 45 , comprising the step of terminating the step of measuring the quantity of the substrate when the second voltage is less than the second predetermined value. 
     
     
         48 . The method of  claim 45 , wherein the reagent layer is provided on at least the first pair of electrodes.