A PETRI CELL MODIFIED FOR ATOMIC-FORCE MICROSCOPY SUITABLE TO INVESTIGATE BIOLOGICAL SAMPLES IN LIQUID

A cell for biological samples that allows atomic force microscopy (AFM ) observations in a controlled environment (air or gas or any liquid) is described. The cell is made of a modified Petri container and it is possible, through two inlet and outlet feedthroughs, to introduce an aqueous liquid during AFM observation thus directly visualizing the mo difications induced on the biological specimen. Uncoated neurons and E scherichia Coli bacteria have been imaged in air and after introducing an aqueous liquid by contact-mode AFM: the microimages an similar and show a comparable resolution even though the force applied to the bio logical material is different. (C) 1998 American Institute of Physics.