We are trying to stain neutrophils in the neonatal hypoxic-ischemic brain. We tested two markers, NE and MPO, but both showed signals not only in neutrophil-like cells (based on morphology) but also in neurons and oligodendrocytes. When we used the same method and concentration on adult stroke brain samples, we observed very specific neutrophil staining.

Does anyone know how to interpret this? The samples we used were FFPE sections, and the processing, sectioning, and staining methods for both neonatal and adult brains were identical.

The antibodies showed very specific signals in the adult brain, indicating that they work well. However, why do they show so much nonspecific staining in neonatal brains? Do we need to use a different method to process and stain neonatal brain tissue?

Thank you very much for any suggestions.

Chunfeng