FIG. 8 is a cross-sectional view of conventional measuring device 501. Measuring device 501 is a cellular electrophysiology sensor. Measuring device 501 includes substrate 1 having partition wall section 3. Substrate 1 has cavities 2 and 5 provided therein. Cavity 5 communicates with cavity 2 via through-hole 4 provided in partition wall section 3.
Cavities 2 and 5 are filled with measuring solution of electrolytic solutions. Then, cell 6, a test object, is injected to cavity 2. When the electrolytic solution is sucked from cavity 5, cell 6 can be captured at opening section of through-hole 4 near cavity 2.
While cell 6 is captured, agent is injected to cavity 2 to measure a potential difference between the electrolytic solutions in cavities 2 and 5 and the current flowing between cavities 2 and 5. Depending on the measured potential difference or current value, a potential change and a current value change at the interior or exterior of cell 6 during the activity of the cell as well as a physicochemical change caused by the activity of the cell can be measured.
Measuring devices similar to conventional measuring device 501 are disclosed in Patent Publication 1 and Patent Publication 2.
In conventional measuring device 501, a deteriorated measuring efficiency may be caused by a defective adhesion or a failed suction of the test object or a loss in the time to inject the measuring solution or agent for example. When cell 6 is measured as a test object in particular, one cell 6 is required to contact one through-hole 4 securely. Generally, an electrophysiological reaction generated by cell 6 (e.g., a potential difference generated at the interior or exterior of the cell or the value of the current flowing the interior or exterior of the cell) is a very small reaction. If cell 6 insufficiently contacts through-hole 4 and produces a gap between cell 6 and partition wall section 3, an electrical leak is caused via the gap. This electrical leak prevents an accurate measuring of the electrophysiological reaction at the interior or exterior of the cell.
In the case that cell 6 is subjected to the defective adhesion as described above, noise caused by the electrical leak prevents the measurement from being carried out accurately, thus failing to provide measuring data. Thus, another measuring device is newly prepared and used to perform the measurement from scratch, thereby causing the measuring of the cell electrophysiological reaction less efficiency.
Furthermore, a deteriorated measuring efficiency is also caused by a solid matter other than the test object (e.g., inactivated cells existing in the measuring solution, dusts other than the cell). Specifically, the solid matter existing in the measuring solution may include not only cell 6 as a test object to be measured but also inactivated cells or dust. Thus, if the inactivated cells or dusts are adsorbed by through-hole 4, measuring data cannot be obtained, thus requiring a measurement to be performed from scratch using a separately-prepared measuring device. This consequently causes the measuring of the cell electrophysiological reaction to have a very low efficiency.
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