The atomic force microscope (AFM) is used to image the surface of both conductors and nonconductors. Biological specimens constitute a large group of nonconductors. A disadvantage of most AFM's is the fact that relatively large areas of the sample surface have to be scanned to pinpoint a biological specimen (e.g. cell, chromosome) of interest. The AFM presented here features an incorporated optical microscope. Using an XY- stage to move the sample, an object is selected with the aid of the optical microscope and a high-resolution image of the object can be obtained using the AFM. Results on chromosomes and cells demonstrate the potential of this instrument. The microscope further enables a direct comparison between optically observed features and topological information obtained from AFM images.
Putman, C. A. J., de Grooth, B. G., van Hulst, N. F., & Greve, J. (1992). Atomic force microscope featuring an integrated optical microscope. Ultramicroscopy, 42(44), 1549-1552. https://doi.org/10.1016/0304-3991(92)90481-X