biopsy tissue that has been prepared to be looked at under a microscope. The tissue is soaked in formaldehyde, processed in various chemicals, enclosed in a block of wax, sliced very thin, attached to a microscope slide, and stained. This process usually takes 1 to 2 days. It allows a clear view of the cells in the sample so that the pathologist can see whether or not cancer is present. Compare with frozen section. See also biopsy, pathologist.