Patent ID: 7462324

Claim:
A measurement device for measuring an electric signal from a biological sample, comprising: a first substrate; and a second substrate formed on the first substrate, wherein the second substrate includes a concave portion thereby forming a flow pass between the first substrate and the second substrate, wherein the flow pass is configured to have a first end and second end, and wherein said flow pass extends in a first direction, from said first end to said second end; a pair of introduction orifices connected to both ends of the flow pass, respectively; a concave well positioned in the flow pass; a reference electrode positioned in the flow pass; at least a microelectrode formed in the well and configured to measure an electric signal from the biological sample; a first communicating tube connected to a first portion of the well and extending in a second direction; a second communicating tube connected to a second portion of the well and extending in a third direction; first and second resistance baths connected to the first and second tubes, respectively; and first and second resistors arranged in the first and second communicating tubes, respectively, or the first and second resistance baths, respectively.