See patchiness of positivity. All anti GFP abs that I have ( that are good for FFPWS ) give identical patterns of positivity.

Hippocampus: note gaps in astrocyte positivity ( as seen with ab290)

Hippocampus Ca1 region: note clusters of positive astrocytes between apparently negative areas. If one carried out a std anti GFAP technique using a well-characterised antibody, no such spaces would be seen

See my DAB images of same area, using antibody ab7260: comments welcome.

Lateral ventricle: negative clusters of cells in the svz ( stained blue with Haemalum)are progenitor olfactory neurones.

Note that not all Bergmann glia are positive ( same with any anti GFP antibody that works well on FFPWS after HIER so not due to antibody sensitivity)

Compare this result with image of sequential section, probing with A11122 anti GFP . Different population of astrocytes? Or just because it is not exactly the same section ( so, I should have double-labelled one section using anti GFP and anti GFAP)

Compare this with image taken of anti GFP A11122 after HIER ( sequential section)