Atomic force microscope with integrated optical microscope for biological applications

Abstract
Since atomic force microscopy (AFM) is capable of imaging nonconducting surfaces, the technique holds great promises for high‐resolution imaging of biological specimens. A disadvantage of most AFMs is the fact that the relatively large sample surface has to be scanned multiple times to pinpoint a specific biological object of interest. Here an AFM is presented which has an incorporated inverted optical microscope. The optical image from the optical microscope is not obscured by the cantilever. Using a XY stage to move the sample, an object is selected with the optical microscope and an AFM image of the selected object can be obtained. AFM images of chromosomes and K562 cells show the potential of the microscope. The microscope further enables a direct comparison between optically observed features and topological information obtained from AFM images