12 
Modern Light 
Microscopy Gives a 
Clear \iew of Cell 
Structure and 
Movement 
Using a microscope the 
size of his palm, Anton 
van Leeuwenhoek was 
ahle to study the move- 
ments of one-celled 
organisms. Modern 
descendants of van 
Leeuwenhoek’s light 
microscope can he over 6 
feet tall, but they con- 
tinue to be indispensable 
to cell biologists because, 
unlike electron micro- 
scopes, light microscopes 
enable the user to see 
living cells in action. The 
primary challenge for 
light microscopists since 
van Leeuwenhoek’s time 
has been to enhance the 
contrast between pale 
cells and their paler 
surroundings so that cell 
structures and movement 
can be seen more easily. 
To do this they have 
devised ingenious strate- 
gies involving video 
cameras, polarized light, 
digitizing computers. 
and other techniques 
that are yielding vast 
improvements in contrast, 
fueling a renaissance in 
light microscopy. 
A polarizer causes light 
waves to move in parallel 
planes, thus reducing the 
distortion that results 
when light scatters across 
a magnified object. This 
technique was first used 
in the 1950’s, and it 
provided many new clues 
to cellular activities, 
particularly the intrica- 
cies of cell division. 
Further enhancements in 
visualizing the cell’s 
interior came in the early 
1980’s, when microscopists 
Shinya Inoue of the 
Marine Biological 
Laboratory in Woods 
Hole, Massachusetts, 
