Upper image of untreated bladder.

Lower image of bladder digested with Chondoitinase before fixing and proceeding to FFPWS.

Digestion leaves “holes” in the normally impervious Umbrella cells, leading to cystitis?

Keratin 20 ( M7019) appears to be confined to Umbrella cells of the urothelium ( lower image)

Upper image is a section probed using a Pan keratin antibody (Abcam ab7753) and is positive for urothelium per se

Positivity is limited to Merkel cells .

After Citric acid HIER plaques and neurone cytoplasm are positive.

Positivity ( of variable intensity) is confined to ganglion cell cytoplasm.