Searching for Life in the Solar System ... And Beyond
A Research Discussion Meeting
London, UK - 31 October 1996

Atomic Force Microscopy Imaging of a Fragment of ALH84001

A Steele, D Goddard, D Stapleton, J Smith, R Tapper and I B Beech

Atomic Force Microscopy [AFM] is a form of Scanning Probe Microscopy [SPM] which allows 3- dimensional imaging of surfaces at extremely high resolutions. Traditionally this microscopy technique has been used to image at the atomic/molecular level, however research has shown that AFM is extremely effective in the imaging of bacterial cells [Steele et al 1994]. The main advantages of this technique are: the ability of this microscope to produce images at a horizontal resolution of 1 nm and the fact that samples need no preparation before imaging.

A sample of ALH84001 has been imaged using Environmental Scanning Electron Microscopy [ESEM], fitted with Energy Dispersive X-Ray Analysis [EDX] and AFM. The combination of these techniques has allowed the location and imaging of both the inner surface of the carbonate globuels and the iron and magnesium rich rims which surround the globules. Imagine of the surface is still ongoing and presented in this poster are the results thus far.

Steele, A., Goddard, D.T., and Beech, I.B. [1994] An Atomic force microscopy study of the biodeterioration of stainless steel in the presence of bacterial biofilms. Int. Biodeterior. Biodegrad. 33[5]: 35-46