© Science Museum / Science & Society
In July 1985, three physicists—Gerd Binnig of the IBM Zurich
Research Laboratory, Christoph Gerber of the University of Basel, and Calvin Quate
of Stanford University—puzzled over a problem while schmoozing at a
microscopy workshop in the Austrian alps: How could they accurately visualize
biological material without destroying it?
The scanning tunneling microscope, which Binnig had co-invented 4 years
earlier, provided atomic resolution without the need for ultra-low temperatures. But
it relied on an electric current flowing through conductive materials. Thus, viewing
biological samples—especially living cells—was out of the
question.
At the workshop, the trio fleshed out a new idea: Instead of measuring
voltage fluctuations, they could simply look for fine-scale changes in miniscule van
der Waals or electrostatic forces. Without the need for a current, such an "atomic
force microscope" (AFM) could reveal the structure of nonconductive materials such
as proteins, organelles, and whole cells.
Immediately thereafter, the three physicists began working "day and night" to
build a prototype, says Gerber. The hard work quickly paid off. A mere 6 months
later, the researchers achieved their first atomic-scale resolution image of a
single graphite crystal. "We were so satisfied that at six o'clock in the morning we
just stepped out of the lab and played a round of golf," Gerber says.
The first prototype AFM (shown here) was rigged to cords and fitted with
metal plates to prevent vibration. On top, a tiny cantilever tip similar to a needle
in a record player grazed across the surface of a material and bent ever-so-slightly
in response to slight atomic force variations. The tip's deflection was then
translated into a three-dimensional image of the sample.
Since then, the simplicity of the AFM concept has spawned dozens of
variations and has been used to explore the terrain of biofilms, measure forces in
motor proteins, and track nanoparticles coursing through a living cell. In the past
25 years, "people have developed it into the most powerful and most sensitive
surface characterization tool that we have," Gerber says.
Ah, the good ol' days...back when I was still in school...and I learned (for bio EM) that you have to:
A) Cover the specimen with GOLD...
B) Let it sit for @3 days...
C) Then (hardest of all!) GET IN LINE FOR Viewing your slide!
D) And now--wa-hoo! Can do, all at once! My Q:
If this tech was around in 1985...howcome we were all still suffering these torments in 1988???
ALTHOUGH...this protocol sure taught us about lab politics in a really expeditions way!
by Dr. Richard Lasker
[Comment posted 2009-06-15 12:17:23]
If this is so, what a break-through in cell discovery; live biologic material, on a nano-scale, for the viewing? Seems impossible.
Sign me up for a demo.