LAP is found in the secondary granules of mature neutrophils. This stain is used to calculate an "LAP Score" based on the intensity of staining in 100 neutrophils.

Remind your audience that while Auer rods are visible on Wright-Giemsa, they are intensely MPO and SBB positive.

SBB mirrors MPO closely but is slightly more sensitive for identifying early myeloid precursors. Like MPO, it is positive in AML. 3. Periodic Acid-Schiff (PAS) What it detects: Glycogen and related mucosubstances. The Result: Bright pink or magenta staining.