7.11.
SPECIFIC ANTIBODY "STAINS"
247
the convenient ways of preserving the tissues (Chapter 3.10). They have
stressed the use of dehydration with water soluble resins, and particularly
glycol methacrylate, which are then used as the embedding media
(Chapter 4.16). They believe that the polar character of these resins
limits their reaction with potential combining groups of the tissue, and
thus tissue components are left in a more nearly native state than would
otherwise be the case. It is quite possible that the "polyampholyte" embedding medium developed by McLean and Singer (1964) will prove particularly useful for these purposes since this leaves intact at least some
specific antigenic properties of tissue (Chapter 4.16), and hence presumably also enzymatic activity. Thus the investigator who would combine
histochemical methods with electron microscopic technique now can foresee excellent opportunities.
7.11. Specific Antibody "Stains"
Fluorescent antibody conjugates have achieved a deserved place in
conventional microscopy since their introduction about a decade ago
for, of course, the antibody finds its specific target, and is then visualized
by the dye it carries with it. Singer and Schick (1961) realized that a
heavy metal conjugate would serve as a marker for electron microscopy
in a way homologous to the manner in which fluorescent dyes are used
conventionally. Singer and Schick proceeded to couple the highly electron
scattering ferritin molecule to an antibody. Ferritin serves as a particularly
useful tag since its tetrahedral structure is positively identifiable with high
resolution electron microscopy, and thus can be distinguished with certainty from contaminations. The ferritin molecule also has great density
since it consists of about 20% iron, but presumably other molecules might
be used instead. Indeed, Pepe and Finck (1961) have conjugated an antibody with an organic mercurial compound, tetraacetooxymercuriarsanilic
acid. Indeed, Pepe, Finck, and Holtzer (1961) even have demonstrated that
under some conditions non-conjugated antibody layers can be visualized
in sectioned material. In private conversation H. Huxley also has indicated that antibodies often can be seen in negatively stained whole
mounts.
Technical problems associated with the preparation and purification
of antibodies and the conjugate molecules involve so much highly specialized detail that it would not be practical to consider this here. What
SPECIFIC ANTIBODY "STAINS"
247
the convenient ways of preserving the tissues (Chapter 3.10). They have
stressed the use of dehydration with water soluble resins, and particularly
glycol methacrylate, which are then used as the embedding media
(Chapter 4.16). They believe that the polar character of these resins
limits their reaction with potential combining groups of the tissue, and
thus tissue components are left in a more nearly native state than would
otherwise be the case. It is quite possible that the "polyampholyte" embedding medium developed by McLean and Singer (1964) will prove particularly useful for these purposes since this leaves intact at least some
specific antigenic properties of tissue (Chapter 4.16), and hence presumably also enzymatic activity. Thus the investigator who would combine
histochemical methods with electron microscopic technique now can foresee excellent opportunities.
7.11. Specific Antibody "Stains"
Fluorescent antibody conjugates have achieved a deserved place in
conventional microscopy since their introduction about a decade ago
for, of course, the antibody finds its specific target, and is then visualized
by the dye it carries with it. Singer and Schick (1961) realized that a
heavy metal conjugate would serve as a marker for electron microscopy
in a way homologous to the manner in which fluorescent dyes are used
conventionally. Singer and Schick proceeded to couple the highly electron
scattering ferritin molecule to an antibody. Ferritin serves as a particularly
useful tag since its tetrahedral structure is positively identifiable with high
resolution electron microscopy, and thus can be distinguished with certainty from contaminations. The ferritin molecule also has great density
since it consists of about 20% iron, but presumably other molecules might
be used instead. Indeed, Pepe and Finck (1961) have conjugated an antibody with an organic mercurial compound, tetraacetooxymercuriarsanilic
acid. Indeed, Pepe, Finck, and Holtzer (1961) even have demonstrated that
under some conditions non-conjugated antibody layers can be visualized
in sectioned material. In private conversation H. Huxley also has indicated that antibodies often can be seen in negatively stained whole
mounts.
Technical problems associated with the preparation and purification
of antibodies and the conjugate molecules involve so much highly specialized detail that it would not be practical to consider this here. What