Glycogen in human skin: FFPWS using PAS technique


Predominantly in stratum spinosal cells. Note that glycogen is assymetrically distributed within each cell ( black arrowhead). This is because of the unidirectional penetration/flow of fixative when a specimen is placed in fixing fluid without agitation: the glycogen is pushed ahead of the wave of fixing fluid until it cannot go further because of the cell membrane.

Melanin within melanocytes is indicated by a yellow arrowhead. After transportation into cells of the basal layer ( red arrowhead), melanin forms a cap over the nuclei ( protecting DNA from  UV light…up to a point!).