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Measurements from electron micrographs of organelle size in relation to their shape: A refinement applied to the epidermal melanosome and basal lamella
Author(s) -
Waterhouse J. P.,
Squier C. A.
Publication year - 1969
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1969.tb00665.x
Subject(s) - organelle , lamella (surface anatomy) , melanosome , electron microscope , ultrastructure , basal lamina , electron micrographs , biophysics , biology , materials science , anatomy , optics , physics , microbiology and biotechnology , melanin , genetics
SUMMARY The mean value of measurements of organelles made from electron‐microscope sections cut in random planes is not an accurate expression of any important dimension of a nonspherical organelle; realistic measurements of organelles in electron micrographs must take into account the three‐dimensional shape of the organelle. Stereological methods offer ways of calculating surface areas and volumes of organelles in electron‐microscope sections but do not provide an easy means of deriving three‐dimensional structures. If, however, the three‐dimensional shape of an organelle is known, it is possible to select profiles which contain what is approximately a major or a minor axis. The frequency distribution of the values from profiles so chosen are skewed, and the median provides the best estimate of the dimension of the organelle. The median and the interquartile range (P 25 –P 75 ) are presented for measurements made in this way of melanosomes and the basal lamella and lamina lucida of mammalian oral epithelium.