Studying Structure and Function of the Heart Cells Using Scanning Ion Conductance Microscopy

Abstract

Scanning ion conductance microscopy (SICM) is a kind of scanning probe microscopy (SPM) that provides images of nonconducting surfaces that are covered with electrolytes, for example plasma membranes of biological cells, composed of non-conducting lipids [1]. Biological surfaces have complex 3D structures associated with complex functions. Real-time investigation of the membrane structure and function of living cells is of utmost importance, however techniques are limited. Conventional microscopy is limited by light diffraction limit (advanced optical imaging reaching a resolution of ~5–100 nm). Non optical methods like atomic force microscopy can reach resolutions up to ~10 nm but the intermittent contact with the sample and the use of force can sometimes distort the biological membrane structures. Techniques like scanning electron microscopy provide high resolution up to ~0.5 nm but it is invasive and the samples require special fixing procedures so that the sample is compromised. A demand for non-optical high resolution imaging of live samples promoted rapid development of SICM [2–6] and its successful application to imaging topography of live biological cells where existing microdomains can be imaged. A particular advantage of SICM technique for imaging biological cells is that it requires no physical contact with the sample and operates at nanoscale resolution. In particular, this offers a unique advantage to studying cardiomyocytes whose plasma membrane is organized into specialized microdomains.