Premium
Choosing the appropriate section thickness in the melamine embedding technique
Author(s) -
Frösch Dieter,
Westphal Christel
Publication year - 1985
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.1365-2818.1985.tb02575.x
Subject(s) - thin section , melamine , biophysics , materials science , cross section (physics) , chemistry , crystallography , composite material , biology , mineralogy , physics , quantum mechanics
SUMMARY When biological materials are infiltrated by a water‐soluble melamine resin and hardened, they become as hard as glass. This is a prerequisite for extreme thin‐sectioning. In this paper, the structural information from unsupported transparent thin sections of beef liver catalase, calf thymus DNA, horse spleen ferritin, insect muscle and rat microtubules is compared to that of normal thin sections. While ferritin molecules (12 nm diameter), microtubule subunits (8 nm long axis) and catalase crystals (8 nm subunit diameter) appear to become mechanically damaged in a 10 nm section (as measured by resectioning), DNA‐molecules (3 nm diameter) are satisfactorily preserved during sectioning. Remarkably, for electron phase contrast imaging of unstained cross‐sectioned insect muscle, a minimum section thickness of about 30–40 nm is required.