This field shows the irregular polyhedral profiles of the muscle fibres with lightly stained transverse sections of myofibrils (*). Interspersed in the cytoplasm of some cells, the purple granulations correspond to accumulations of glycogen. Note the variations in the numbers of purple glycogen particles (arrows) in the cytoplasm of the various muscle cells.

The PAS technique also stains the basement membrane (M), with its abundant carbohydrate-rich type III collagen. This thin amorphous layer is closely associated with the cytoplasmic membrane (not visible) of muscle cells.

Stain: PAS-Hematoxylin
Magnification: ×900