While the term immunohistochemistry (IHC) is often used interchangeably with immunocytochemistry (ICC), significant differences exist between IHC and ICC in terms of the biological sample that is analyzed. Simply put, IHC is performed on samples derived from tissues that have been histologically processed into thin sections and the staining process exploits enzymes which catalyze the deposition of a colored staining product at antigenic sites within the sample. ICC relies on the same enzyme reactions as IHC, but it is performed on samples consisting of cells grown in a monolayer or cells in suspension which are deposited on a slide. However, on our website and elsewhere, it is much more common to see ICC used generically to describe immunofluorescence (IF) staining of tissue sections or cells.