For IHC? To stain neutrophils in tissue right? Well we usually don't since they don't look the same and you can tell pretty easily just using H&E.

For flow markers, you can use CD66b and CD11b (monocytes won't have CD66b, but eosinophils will. If you want that distinction, you will need to add CD16 (but there is a subset of monocytes that will express CD16). So it becomes a gating strategy.

This would be the same if you were looking at tissue samples, since macrophages should have the same profile with these markers compared to the blood monocytes.

Hi, neutrophil is CD16 positive and CD15 negative, while eosinophil is CD15 positive and CD16 negative.

Thanks!