Three-dimensional arrangement of sarcoplasmic reticulum in crayfish as seen by high voltage electron microscope.

Sections several micro thick of single fibres from the crayfish muscle were examined by means of a high voltage electron microscope to find out the geometry of the sarcoplasmic reticulum (SR). A sufficient contrast of the SR was achieved by lead acetate histochemical method for calcium. Longitudinally oriented files of SR vesicles at the level of A bands and interruptions in otherwise continuous SR net are the most conspicuous features.