The tissue is usually sectioned on a cryostat or freezing microtome. The cut edge is then thinly sliced with a microtome or a cryostat. The cryostat is essentially an ultrafine "deli-slicer", called a microtome, placed in a freezer. NanoSIMS can be combined with transmission electron microscopy (TEM) when using microtome or FIB sections. In a rotary microtome, the knife is typically fixed in a horizontal position. The laser microtome is an instrument for contact-free slicing. It is similar to a microtome but uses a vibrating blade to cut through tissue. Once frozen, the specimen on the chuck is mounted on the microtome. The vibrating microtome is usually used for difficult biological samples. The microtome of this type has a recessed rotating saw, which slices through the sample. The laser microtome has the ability to slice almost every tissue in its native state. Decalcification is necessary to obtain soft sections of the bone using a microtome. A variation on the vibrating microtome is the Compresstome microtome. He improved upon various techniques in neuro-anatomy including modifications to Gudden's microtome design. First, a thin section of the sample is cut, often using a microtome.