Base sequence detection apparatus and base sequence automatic analyzing apparatus

Abstract

A base sequence detection apparatus is provided with a channel formed on a base sequence detection chip. Working electrodes are formed along the channel and include a probe immobilized thereon, counter electrodes are formed on the inner surface of the channel and, reference electrodes are formed on the inner surface of the channel. An introduction port introduces solution or air from the upstream side of the channel, a delivery port delivers the solution or air in the channel, and the sample is injected into the channel through a sample injection port.

1 . An automatic base sequence analyzing apparatus for executing a measurement to analyze a base sequence of a sample by applying a voltage to a counter electrode of a base sequence detecting unit when the base sequence detecting unit is attached to the automatic base sequence analyzing apparatus,
 wherein the base sequence detecting unit includes a working electrode to which a probe having a predetermined base sequence is fixed, a reference electrode and the counter electrode, comprising:   a voltage pattern generator which generates a voltage pattern to be applied to the counter electrode;   a feedback circuit which feeds a voltage of the reference electrode back to the counter electrode;   a first amplifier which amplifies a voltage generated on the basis of the voltage from the voltage pattern generator and the feedback circuit, and applies the amplified voltage to the counter electrode;   a first resistance arranged between input and output terminals of the first amplifier or between the first amplifier and the counter electrode;   a switch which ON/OFF-controls a current flowing into the first resistance;   a second amplifier connected to the working electrode; and   a second resistance arranged between input and output terminals of the second amplifier, which generates a voltage signal as a measurement signal which is output from the second amplifier.   
   
   
       2 . The automatic base sequence analyzing apparatus according to  claim 1 , wherein the base sequence detecting unit includes a plurality of working electrodes, the automatic base sequence analyzing apparatus further comprising:
 a signal switching unit provided between the working electrodes and the second amplifier to switch the connection of the second amplifier to the working electrodes.   
   
   
       3 . The automatic base sequence analyzing apparatus according to  claim 1 , further comprising:
 a computer including a main processor and an interface; and   a control unit which is connected to a local bus through the interface and is operated under the control of the computer, the control unit including a measurement unit which controls the voltage pattern generator to generate the voltage pattern and which converts the measurement signal into measurement data, and a data memory which stores the measurement data.   
   
   
       4 . The automatic base sequence analyzing apparatus according to  claim 3 ,
 wherein the base sequence detecting unit includes a plurality of working electrodes,   the measurement unit comprises a signal detecting unit which sequentially detects the measurement signals, and includes a signal switching part which switches the connection to the working electrodes, and   the signal detecting unit AD-converts the measurement signals into the measurement data and stores the measurement data in the data memory, the measurement signals being obtained by the signal switching part switching connections to the working electrodes, respectively.   
   
   
       5 . The automatic base sequence analyzing apparatus according to  claim 3 ,
 wherein the base sequence detecting unit includes a plurality of working electrodes,   the measurement unit comprises a signal detecting unit which sequentially detects the measurement signals and includes a signal switching part which switches the connection to the working electrodes, and a timing signal generator which controls the signal switching part, and   the signal detecting unit AD-converts the measurement signals into the measurement data and stores the measurement data in the data memory in a timing given by a write signal which is generated by the timing signal generator, at an address which is given for every write signal, the measurement signals being obtained by the signal switching part switching connections to the working electrodes, respectively.   
   
   
       6 . The automatic base sequence analyzing apparatus according to  claim 3 ,
 wherein the base sequence detecting unit includes a plurality of working electrodes,   the measurement unit comprises a signal detecting unit which sequentially detects the measurement signals, and includes a signal switching part which switches the connection to the working electrodes, a timing signal generator which controls the signal switching part, and an operation setting unit which sets an operating mode utilized to execute measurements of a predetermined number of the working electrodes within measurement time intervals, respectively,   in the operating mode,   the signal detecting unit converts the measurement signals each of which is supplied from the predetermined number of working electrodes via the signal switching part within the measurement time interval, into a digital signal, and stores the digital signal as the measurement data in the data memory in a timing given by write signals which is generated by the timing signal generator, at an address which is given for every write signal by the timing signal generator,   the write signals which are generated a predetermined number within the measurement time interval by the timing signal generator.