Miniature Serial Microtome for Block-Face Imaging

A microtome device is used in a variety of microcopy techniques to remove very thin (e.g., in the tens of nanometers range) portions from the top of a sample between successive images. This technology discloses a design for a microtome device that offers several unique features and advantages over commercially available microtomes. A prototype of the microtome has been built and demonstrated to work with a serial block-face scanning electron microscopy in order to serially collect ultrathin sections from plastic embedded biological tissues, specifically from brain tissues. This microtome design allows for a sample to be cut at a location removed from the electron beam axis, thus reducing interference from debris and allowing imaging at a greater range of working distances. This microtome device is lightweight and easy to install utilizing the built-in stage of existing microscopes such that a sample's position and orientation can be controlled along three-axes of rectilinear translation and two axes of rotation. This microtome design utilizes a diamond blade coupled to both the base plate and an actuator to control the movement of the blade in a direction perpendicular to the exposed surface of the pedestal, while producing an output signal that indicates the blade location with respect to the base plate. Advantageously, this allows for a stage coupled pedestal to be moved accurately from an imaging location on the beam axis to a cutting location off the beam axis.