Page 8 - Flow Cytometry Protocols Fourth Edition

Flow Cytometry: The Glass Is Half Full
clothes. I could see distinctly the limbs of these vermin with my naked eye, 3
much better than those of a European louse through a microscope, and their
snouts with which they rooted like swine.
Gulliver's last two sentences make it clear that Swift had some
familiarity with Hooke's book; the drawings of the louse undoubt-
edly attracted more attention from the lay audience than did those
of the cork slices.
Although I didn't get around to it until after I wrote my
cytometry book [l], I've been through Micrographia at least a
couple of times. When I have asked how many people in audiences
listening to Hooke Lectures at ISAC meetings have read it, how-
ever, I haven't seen a lot of hands go up. That may explain why
there are so many places on the Internet in which it is erroneously
claimed the analogy was made to cells in a monastery or prison.
This cytometric urban legend, like the notion that forward scatter
measures cell size, is harder to kill than Dracula. Micrographia is
fascinating for many reasons, written in understandable English,
and available free online; I modestly propose you read it if you
haven't.
Hooke did not actually see living cells until years after "Micro-
graphia" was published, when the Royal Society asked him to check
up on reports from a self-taught Dutch fabric merchant, Antoni van
Leeuwenhoek, who used simple microscopes of his own design that
provided much higher magnification than was available from the
compound microscopes then used by Hooke and others. The
property van Leeuwenhoek used to distinguish "animate" particles,
now known as cells, from "inanimate" ones was motility, which
kept him obsessively interested in bacteria, protozoa, sperm, and
other "animalcules" and largely indifferent to yeast and the consid-
erable contributions it had made to humanity over the millennia.
Many early microscopists anticipated that improvements in
optics would quickly enable them to visualize atoms; they also
tended to attribute morphological and biological characteristics of
humans and other vertebrates to microorganisms, in which Van
Leeuwenhoek notably estimated the sizes of livers, kidneys, and
other internal organs he expected would eventually be discernible.
The expectation that the parts would scale as did the wholes was
incorrect. A real Gulliver might have known what a microscope was;
he would not have known what a cell was. What we now call cells
were known by many other names until the mid-1800s, by which
time improvements in microscopy including substage condensers
and achromats and other lenses that reduced aberrations and
increased resolution had made it easier to distinguish biologic
structures from artifacts. Both Matthias Schleiden and Theodor
Schwann, prime movers of but hardly sole contributors to what
has been known since that time as the cell theory [I], used and
favored the term. Whereas Hooke had used it to describe an empty