Diff-Quick is a commercial Romanowsky-type stain in common use for cell and microorganism evaluation. Blood, other body fluids, tissue aspirates, and impressions of tissue surfaces are microscopically examined following staining. The staining protocol is quick and easy.
To prepare a slide for staining, a technician uses a clean dry microscope slide. He smears or impresses a sample on the slide and then air dries the slide prior to Diff-Quick staining.
Diff-Quick stain is sold in kits. Kits contain three solutions. The technician places each solution in a clean, lidded container suitable for dipping of prepared slides. The first solution contains a fixative, the second contains a red stain and the third contains a blue counterstain.
The technician then dips the slide with dried sample, either for a few seconds or repeatedly for one second intervals, sequentially into each of the three solutions. Between each solution, the technician may rinse the slide in distilled water, and briefly allows excess stain and fluid to drain from the slide surface.
After dipping in the third solution, the technician rinses the slide in distilled or tap water and air dries or blots the slide using care to avoid damaging the sample, which is then ready to be examined by microscopy. The entire procedure is usually completed in about five minutes.
Variations in technique
The sample slide may be flooded with solutions instead of dipped. The length of time the slide is immersed in solution is varied according to sample characteristics, with more time needed for thicker samples.