| Method |
"[Researchers] used the point counting method to estimate the volume fraction of the various compartments in S. pombe cells from electron micrographs (S8 = M. Morphew, J. R. McIntosh, unpublished data) of thin sections of quick-frozen, freeze-substituted cells. A square grid of test points was positioned over each EM image and scored as being over one of four compartments: cytoplasm, ribosomes, membrane-bounded organelles, and cell wall. The technique is based on the principle that the ratio of the area of a compartment to that of the whole cell is proportional to the ratio of volume in random thin sections. [Researchers] found that cytoplasm occupies 29% and the nucleus 12% of cell volume." |