Wayson stain of Yersinia pestis showing characteristic safety pin appearance

Yersinia pestis smears stained by Giemsa or Methylene blue, bipolar staining is seen, which is referred to as safety pin appearance. The ends are densely stained with a pale stained centre.

1. Wayson stain
2. Causative organism of plague
3. Draughtsman appearance
4. Carrom coin appearance