Immunohistochemistry (or IHC) is a technique that utilizes antibodies (primary and secondary) conjugated to proteins to help visualize and localize those specific proteins in a tissue sample. This process is typically done using thin tissue sections. Immunohistochemistry can be completed in a few steps. First, the tissue sample must be “fixed” or preserved using chemicals like paraformaldehyde or formalin. Fixed tissue stabilizes the structural integrity of cells and proteins, preventing them from deteriorating or changing during the rest of the IHC process. Tissue samples must then be sectioned to get very thin slices, typically 5µm to 50µm thick. Primary antibodies against the target protein are added to tissue slices, followed by secondary antibodies. The secondary antibodies may have a fluorophore to allow for visualization of the specific protein during imaging.
Because immunohistochemistry requires thin sections of tissue, it is crucial to be able to obtain consistent, reliable tissue slices of uniform thickness. Getting such slices can be done using vibrating microtomes (vibratomes) and rotary microtomes.