AN ATOMIC-FORCE MICROSCOPE FOR CYTOLOGICAL AND HISTOLOGICAL INVESTIGATIONS

An atomic force microscope (AEM) specifically designed for cytological and histological studies and able to operate on the same scale of the highest optical magnification is described. The APM is a non-invasive instrument; it operates on samples which do not require any kind of t reatment and it can produce information that supplements and completes the information given by traditional microscopical methods. The appar atus has been used to image fixed human chromosomes and to investigate the action of trypsin during the staining for banding. First results showed that banding patterns very similar to G-banding pre-exist to st aining and to trypsin treatment in human metaphase chromosomes, and th at the trypsin treatment induces a structural collapse in the chromati n. The instrument was also used on thin sections of plant tissue and g ave promising results. Experience confirmed that AFM is a suitable too l for this kind of investigation, and proved the importance of develop ing AFM microscopes specifically designed for routine use in cytology and histology, conceived for non-specialized users.