SCANNING NEAR-FIELD OPTICAL ATOMIC FORCE MICROSCOPY FOR FLUORESCENCE IMAGING AND SPECTROSCOPY OF BIOMATERIALS IN AIR AND LIQUID - OBSERVATION OF RECOMBINANT ESCHERICHIA-COLI WITH GENE CODING TO GREEN FLUORESCENT PROTEIN/

We have developed a system of scanning near-field optical/atomic force microscopy (SNOM/AFM) for fluorescence imaging and spectroscopy of bi omaterials in air and liquid. SNOM/AFM uses a bent optical fiber simul taneously as a dynamic force AFM cantilever and a SNOM probe. Optical resolution of SNOM images shows about 56 nm in an illumination mode fo r a standard sample of a patterned chromium layer of 20 nm thickness o n a quartz glass plate. The SNOM/AFM system contains a photon counting system and polychrometer/ICCD (intensified charge coupled device) sys tem for observation of the fluorescence image and spectrograph of micr o areas, respectively. The gene coding to green fluorescence protein ( GFP) was cloned in recombinant Escherichia coli (E. coli). Topography, fluorescence image and spectrograph of recombinant E. coli by SNOM/AF M showed a difference in fluorescence in individual E. coli. Fluoresce nce activity of GFP can thus be used as a convenient indicator of tran sformation. SNOM/AFM is also applicable to observe immobilized E. coli on a glass plate in water with a liquid chamber and may allow the vie wing of observation of floating organisms.