Premium
The estimation of distances between parallel membranes on thick sections
Author(s) -
CasleySmith J. R.,
Davy Pamela
Publication year - 1978
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.1365-2818.1978.tb00135.x
Subject(s) - membrane , stain , perpendicular , surface (topology) , section (typography) , contrast (vision) , cross section (physics) , geometry , block (permutation group theory) , optics , materials science , chemistry , mathematics , physics , staining , biology , computer science , biochemistry , genetics , quantum mechanics , operating system
SUMMARY Since sections intersect membranes at random angles, the mean distances measured between two such membranes are greater than the perpendicular distances between them. Errors of 10–20% will be usual. Equations are derived relating the true lengths with the various observed ones, and the accuracy of the various methods are indicated. These differ for block‐stained and section‐stained material. In the Appendix it is shown that in section‐stained material, while it is the stain near the surface which is of overwhelming importance for the production of contrast, much of this stain lies in the section itself, rather than actually on the surface. This stained depth is shown to be ∼4 nm deep, but this depth may include surface aggregates (∼ 1 nm) as well.