Scanning tunneling microscopy of microtubules

Scanning tunneling microscopy (STM) was used to image neuronal microtubules, protein polymers which may be capable of information processing. Isolated microtubules fixed in 0.1% glutaraldehyde in reassembly buffer containing 0.8 M glycerol were imaged in air on a graphite substrate. STM probing showed structures approximately 25 nm in width, consisting of longitudinal filaments of about 4 nm width. These images match electron micrographs of microtubules and their component protofilaments. >