A scanning force microscopy study of human serum albumin and porcine pancreas trypsin adsorption on mica surfaces

• Published in: Surface science 1995, Vol.325 (1), p.L406-L412
• Main Authors: Quist, A.P., Björck, L.P., Reimann, C.T., Oscarsson, S.O., Sundqvist, B.U.R.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Molecular biophysics; Surface properties. Adsorption
• ISSN: 0039-6028; 1879-2758; 1879-2758
• DOI: 10.1016/0039-6028(94)00809-4

Scanning force microscopy is more and more expanding as a tool for biological research. Here we report about the observation of molecular adsorption on mica surfaces. Human serum albumin and porcine pancreas trypsin were adsorbed on freshly cleaved mica from the solution phase. The new tapping mode (intermittent contact) scanning force microscopy technique was employed to image the molecules on the surface. We observed clusters of molecules and features which we interpret as single molecules adsorbed on the mica. For albumin, we could sometimes resolve structures corresponding to the three main domains of which albumin is composed. Analysis of lateral sizes and height, as well as scanning artefacts, are discussed. We observed the ability of the tapping mode to modify the distances between the respective domains in albumin and to split clusters into smaller parts.