12
1. LABORATORY ORGANIZATION AND MANAGEMENT
problems that can be straightforwardly dealt with in the latter instance,
should be all the better answered by the new technique. One has to convince these people that electron microscopy inevitably proceeds at a much
slower pace so that the "simple" problem which might take only weeks
with a light microscope may take a similar number of years with the
electron microscope. Furthermore, one must persuade these people that
the sluggishness has nothing to do with one's energies or abilities, but is
intrinsic to the method. In short, these people must be educated!
A few figures relating to dimensions help explain the problem. If one
uses the standard "200 mesh" supporting screens, there is just about
1 mm
2
of open area that can be viewed by microscopes which take J-in.
screens. Even assuming that this square millimeter might be covered by
perfect sections (which would be as rare as a Royal Flush in honest
poker), it would take screens by the hundreds to be the equivalent of one
ordinary section that the pathologist perhaps deals with in five minutes
or less. When one has good and interesting material it is quite reasonable
to spend a half day or more on a single grid. In this time one sees less
than a square millimeter of surface, and cannot possibly photograph
more than a tenth of this even at low magnification. At this rate it would
take a solid year of work to record what the light microscopist can dismiss while he smokes one cigarette.
If we juggle the figures differently, and take a picture at only X 1500
on a 2-in. plate, we record but 0.001 mm
2 . It is a rare day that one has
material that warrants taking more than 50 pictures (which, of course,
would not generally be at such a low average magnification). Even so,
though, it would take the better part of a month actually at the microscope to photograph 1 mm
2 , and 7\ years of continuous photography to
photograph 1 cm
2 .
If one considers the third dimension, the problem is, of course, much
worse. Useful sections can be no more than 1 /20 \i thick. Twenty serial
sections traverse a single micron. They perhaps span the thickness of one
mitochondrion. It would take 100 sections to get through a nucleus, and
200 sections to record the volume of a single small cell. The conventional
embryologist rarely needs as many sections to go through an entire pig
embryo!
An electron microscopist who is concerned with tissue work simply
cannot accept most problems that are primarily statistical. He cannot
possibly process enough samples. He can only effectively deal with problems which yield simple qualitative answers. Processes that involve
1. LABORATORY ORGANIZATION AND MANAGEMENT
problems that can be straightforwardly dealt with in the latter instance,
should be all the better answered by the new technique. One has to convince these people that electron microscopy inevitably proceeds at a much
slower pace so that the "simple" problem which might take only weeks
with a light microscope may take a similar number of years with the
electron microscope. Furthermore, one must persuade these people that
the sluggishness has nothing to do with one's energies or abilities, but is
intrinsic to the method. In short, these people must be educated!
A few figures relating to dimensions help explain the problem. If one
uses the standard "200 mesh" supporting screens, there is just about
1 mm
2
of open area that can be viewed by microscopes which take J-in.
screens. Even assuming that this square millimeter might be covered by
perfect sections (which would be as rare as a Royal Flush in honest
poker), it would take screens by the hundreds to be the equivalent of one
ordinary section that the pathologist perhaps deals with in five minutes
or less. When one has good and interesting material it is quite reasonable
to spend a half day or more on a single grid. In this time one sees less
than a square millimeter of surface, and cannot possibly photograph
more than a tenth of this even at low magnification. At this rate it would
take a solid year of work to record what the light microscopist can dismiss while he smokes one cigarette.
If we juggle the figures differently, and take a picture at only X 1500
on a 2-in. plate, we record but 0.001 mm
2 . It is a rare day that one has
material that warrants taking more than 50 pictures (which, of course,
would not generally be at such a low average magnification). Even so,
though, it would take the better part of a month actually at the microscope to photograph 1 mm
2 , and 7\ years of continuous photography to
photograph 1 cm
2 .
If one considers the third dimension, the problem is, of course, much
worse. Useful sections can be no more than 1 /20 \i thick. Twenty serial
sections traverse a single micron. They perhaps span the thickness of one
mitochondrion. It would take 100 sections to get through a nucleus, and
200 sections to record the volume of a single small cell. The conventional
embryologist rarely needs as many sections to go through an entire pig
embryo!
An electron microscopist who is concerned with tissue work simply
cannot accept most problems that are primarily statistical. He cannot
possibly process enough samples. He can only effectively deal with problems which yield simple qualitative answers. Processes that involve