Premium
An electron‐optical lens effect as a possible source of contrast in biological preparations
Author(s) -
Haydon Glen B.
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.tb00690.x
Subject(s) - contrast (vision) , optics , lens (geology) , stain , electron microscope , aperture (computer memory) , high contrast , materials science , numerical aperture , microscope , biological specimen , image contrast , optical microscope , scanning electron microscope , staining , physics , biology , wavelength , genetics , acoustics
SUMMARY Heavy‐metal stain aggregates on the surface of thin sections of biological material have higher contrast than those embedded within the sections and both have greater contrast than can be accounted for by the amplitude image. Disturbances of the incident illumination by a specimen in both light‐ and electron‐optical systems and their possible contribution to image contrast are considered. The hypothesis is proposed that a lens effect produced by the stain aggregates may account for their contrast in the electron microscope in a similar manner to the contrast of glass beads in the light microscope with a low numerical aperture.