Diff-Quik Stain is widely used in clinical and laboratory settings for rapid staining of cytological and histological specimens. It is especially valuable for quickly assessing cell morphology in fine needle aspirates, blood smears, and body fluid samples. The stain differentiates cellular components effectively, highlighting nuclei in blue-purple and cytoplasmic elements in shades of pink and red, allowing for immediate microscopic evaluation.

It is commonly applied in point-of-care testing and intraoperative consultations where fast turnaround time is critical. Due to its speed and reliability, Diff-Quik is preferred for staining specimens in veterinary medicine as well as human pathology. The method is less suitable for detailed nuclear chromatin assessment compared to Papanicolaou staining but excels in providing rapid, clear visualization of cellular details for preliminary diagnosis.