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Scanning ion-conductance microscopy (SICM) is a scanning probe microscopy technique that uses an electrode as the probe tip.〔P.K. Hansma, B. Drake, O. Marti, S.A. Gould and C.B. Prater, Science 243, 641 (1989)〕 SICM allows for the determination of the surface topography of micrometer and even nanometer-range 〔Shevchuk, A.I.; Frolenkov, G.I.; Sánchez, D.; James, P.S.; Freedman, N.; Lab, M.J.; Jones, R.; Klenerman, D.; Korchev, Y.E. Imaging proteins in membranes of living cells by high-resolution scanning ion conductance microscopy. Angew. Chem. Int. Ed. Engl. 2006, 45, 2212–2216.〕 structures in aqueous media conducting electrolytes. The samples can be hard or soft, are generally non-conducting, and the non-destructive nature of the measurement allows for the observation of living tissues and cells, and biological samples in general. It is able to detect steep profile changes in samples 〔Rheinlaender, J.; Geisse, N.A.; Proksch, R.; Schäffer, T.E. Comparison of scanning ion conductance microscopy with atomic force microscopy for cell imaging. Langmuir 2011, 27, 697–704.〕 and can be used to determine the mobility of living cells during their migrations 〔Happel, P.; Wehner, F.; Dietzel, I.D. Scanning ion conductance microscopy–a tool to investigate electrolyte-nonconductor interfaces. In Modern Research and Educational Topics in Microscopy; FORMATEX: Badajoz, Spain, 2007; pp. 968–975.〕 == Working principle == Scanning ion conductance microscopy is a technique using the increase of access resistance in a micro-pipette in an electrolyte-containing aqueous medium when it approaches a poorly conducting surface. It monitors the ionic current flowing in and out of the micro/nano-pipette, which is hindered if the tip is very close to the sample surface since the gap through which ions can flow is reduced in size. The SICM setup is generally as follows: A voltage is applied between the two Ag/AgCl electrodes, one of which is in the glass micro-pipette, and the other in the bulk solution. The voltage will generate an ionic current between the two electrodes, flowing in and out of the micro-pipette. The conductance between the two electrodes is measured, and depends on the flux of ions. Movements of the pipette are regulated through piezoelectrics. The micro-pipette is lowered closer and closer to the sample until the ionic flux starts to be restricted. The conductance of the system will then decrease (and the resistance will increase). When this resistance reaches a certain threshold the tip is stopped and the position recorded. The tip is then moved (in different ways depending on the mode used, see below) and another measurement is made in a different location, and so on. In the end, comparing the positions of all the measurements provides a detailed height profile of the sample. It is important to note that the tip is stopped before contacting the sample, thus it does not bend nor damage the surface observed, which is one of the major advantage of the SICM. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Scanning ion-conductance microscopy」の詳細全文を読む スポンサード リンク
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