Special stains in cytology: a technique using one half of a previously stained slide

We describe a technique for performing special stains on one half of a slide previously stained by the Papanicolaou or Diff-Quick method. The technique varies depending on whether incubation is required during the staining procedure. For stains that do not require incubation, the portion of the slide to be preserved is covered with liquid paraffin. For stains that do require incubation, the area to be preserved is coverslipped with mounting medium and dried overnight prior to staining. The technique is easy, rapid, inexpensive, and enhances diagnostic accuracy.