Scanning Ion Conductance Microscopy of Live Keratinocytes

V. Hegde, A. Mason, T. Saliev, Frances Smith, W. H. I. McLean, P. A. Campbell

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Citation (Scopus)

    Abstract

    Scanning ion conductance microscopy (SICM) is perhaps the least well known technique from the scanning probe microscopy (SPM) family of instruments. As with its more familiar counterpart, atomic force microscopy (AFM), the technique provides high-resolution topographic imaging, with the caveat that target structures must be immersed in a conducting solution so that a controllable ion current may be utilised as the basis for feedback. In operation, this non-contact characteristic of SICM makes it ideal for the study of delicate structures, such as live cells. Moreover, the intrinsic architecture of the instrument, incorporating as it does, a scanned micropipette, lends itself to combination approaches with complementary techniques such as patch-clamp electrophysiology: SICM therefore boasts the capability for both structural and functional imaging. For the present observations, an ICnano S system (Ionscope Ltd., Melbourn, UK) operating in 'hopping mode' was used, with the objective of assessing the instrument's utility for imaging live keratinocytes under physiological buffers. In scans employing cultured HaCaT cells (spontaneously immortalised, human keratinocytes), we compared the qualitative differences of live cells imaged with SICM and AFM, and also with their respective counterparts after chemical fixation in 4% paraformaldehyde. Characteristic surface microvilli were particularly prominent in live cell imaging by SICM. Moreover, time lapse SICM imaging on live cells revealed that changes in the pattern of microvilli could be tracked over time. By comparison, AFM imaging on live cells, even at very low contact forces (<nN), could not routinely image microvilli: rather, an apparently convolved image of the underlying cytoskeleton was instead prevalent. We note that the present incarnation of the commercial instrument falls some way behind the market leading SPMs in terms of technical prowess and scanning speed, however, the intrinsic non-obtrusive nature of SICM imaging leads us to advocate its use for monitoring the most delicate living structures with attendant high spatial resolutions.

    Original languageEnglish
    Title of host publicationElectron Microscopy and Analysis Group Conference 2011 (EMAG 2011)
    Place of PublicationBristol
    PublisherIOP Publishing Ltd.
    Pages-
    Number of pages4
    ISBN (Print)*****************
    DOIs
    Publication statusPublished - 2012
    EventElectron Microscopy and Analysis Group Conference 2011 - Birmingham, United Kingdom
    Duration: 6 Sep 20119 Sep 2011

    Conference

    ConferenceElectron Microscopy and Analysis Group Conference 2011
    Abbreviated titleEMAG 2011
    CountryUnited Kingdom
    CityBirmingham
    Period6/09/119/09/11

    Cite this

    Hegde, V., Mason, A., Saliev, T., Smith, F., McLean, W. H. I., & Campbell, P. A. (2012). Scanning Ion Conductance Microscopy of Live Keratinocytes. In Electron Microscopy and Analysis Group Conference 2011 (EMAG 2011) (pp. -). IOP Publishing Ltd.. https://doi.org/10.1088/1742-6596/371/1/012023