A non-contact mode scanning force microscope optimised to image biological samples in liquid

Given that biological samples are particularly soft in their natural state and that a liquid is the most difficult operating environment for non-contact mode scanning force microscopy, the development of a scanning force microscope that is optimised to image biological samples in vitro presents significant challenges. The performance of the instrument described here has been optimised for such an application by incorporating magnetic excitation and active-Q control of the cantilever. The application of this instrument has been validated by imaging monolayers of immobilised antibodies in liquid and achieving image qualities comparable to those achieved in air for such samples.