4.16.
WATER-SOLUBLE RESIN EMBEDDING
123
later became available commercially through Fluka AG Chemische
Fabrik, Buchs SG, Switzerland, under the trade name of Durcupan.
Presently, it is being marketed also by the International Chemical and
Nuclear Corp., City of Industry, California.
Rosenberg, Bartl, and Lesko (1960) introduced a water-soluble methacrylate, glycol methacrylate, produced by Chemapol, Panska 9, Prague.
This is said to be 2-hydroxyethyl methacrylate, and as such also is
available from Rohm and Haas, Philadelphia, along with an apparently
superior, related compound, 2-hydroxypropyl methacrylate, which is
presently being studied by Leduc and Holt.
The investigational family working with Dr. Wilhelm Bernhard in
Paris has been particularly interested in this group of embedments.
Leduc and Bernhard (1961, 1962) and Leduc, Marinozzi, and Bernhard
(1963) summarize some of their experience. Also, these investigators
have presented major talks dealing with techniques at the 5th International Congress of Electron Microscopy (1962), and the 1963 national
meeting of the Electron Microscope Society of America. It is hoped that
most of what follows is a reasonably accurate expression of their current
views, and this writer frankly admits little personal experience.
Durcupan is at least partly soluble after polymerization, and is fairly
soft at best. Therefore it is particularly difficult to section when used as
the sole resin. It is no longer to be recommended except as a blending
agent. In the latter role, it apparently can be combined in minor quantities as a component in other epoxy mixtures, particularly Araldite. It
then acts to soften the block somewhat, and is said to improve sectioning
qualities. Perhaps more importantly, it may improve the stainability of
the embedded tissue, although a systematic exploration of this aspect
of its usefulness has not been reported.
Aquon preserves tissue better than Durcupan, and sections fairly well.
It apparently acts to some extent as a fixative, however, for Aquon-embedded aldehyde-fixed tissue is not as susceptible to pepsin digestion as
similar material embedded in Durcupan, and particularly material embedded in glycol methacrylate (Leduc and Bernhard, 1962). Thus, Aquon
seems less interesting than the latter for histochemical work.
Aldehyde-fixed tissue embedded in glycol methacrylate is extremely
sensitive to a variety of enzymatic digestions which make this and related compounds most interesting embedding compounds for histochemistry. The most recent information (1963) indicates that 2-hydroxypropyl methacrylate has superior characteristics. The latter compound
WATER-SOLUBLE RESIN EMBEDDING
123
later became available commercially through Fluka AG Chemische
Fabrik, Buchs SG, Switzerland, under the trade name of Durcupan.
Presently, it is being marketed also by the International Chemical and
Nuclear Corp., City of Industry, California.
Rosenberg, Bartl, and Lesko (1960) introduced a water-soluble methacrylate, glycol methacrylate, produced by Chemapol, Panska 9, Prague.
This is said to be 2-hydroxyethyl methacrylate, and as such also is
available from Rohm and Haas, Philadelphia, along with an apparently
superior, related compound, 2-hydroxypropyl methacrylate, which is
presently being studied by Leduc and Holt.
The investigational family working with Dr. Wilhelm Bernhard in
Paris has been particularly interested in this group of embedments.
Leduc and Bernhard (1961, 1962) and Leduc, Marinozzi, and Bernhard
(1963) summarize some of their experience. Also, these investigators
have presented major talks dealing with techniques at the 5th International Congress of Electron Microscopy (1962), and the 1963 national
meeting of the Electron Microscope Society of America. It is hoped that
most of what follows is a reasonably accurate expression of their current
views, and this writer frankly admits little personal experience.
Durcupan is at least partly soluble after polymerization, and is fairly
soft at best. Therefore it is particularly difficult to section when used as
the sole resin. It is no longer to be recommended except as a blending
agent. In the latter role, it apparently can be combined in minor quantities as a component in other epoxy mixtures, particularly Araldite. It
then acts to soften the block somewhat, and is said to improve sectioning
qualities. Perhaps more importantly, it may improve the stainability of
the embedded tissue, although a systematic exploration of this aspect
of its usefulness has not been reported.
Aquon preserves tissue better than Durcupan, and sections fairly well.
It apparently acts to some extent as a fixative, however, for Aquon-embedded aldehyde-fixed tissue is not as susceptible to pepsin digestion as
similar material embedded in Durcupan, and particularly material embedded in glycol methacrylate (Leduc and Bernhard, 1962). Thus, Aquon
seems less interesting than the latter for histochemical work.
Aldehyde-fixed tissue embedded in glycol methacrylate is extremely
sensitive to a variety of enzymatic digestions which make this and related compounds most interesting embedding compounds for histochemistry. The most recent information (1963) indicates that 2-hydroxypropyl methacrylate has superior characteristics. The latter compound