The art of science

Photo of cell division garners Professor John Henson a Nikon award.

November 21, 2006

Biology Professor John Henson. Photo by Carl Socolow '77

While the Day-Glo green chrysanthemums could be a stop-action photo of a fireworks display or the imagined eye sockets of an alien creature, this image represents something much more powerful—a sea-urchin embryo's first step to adulthood.

Cell biologist/researcher John Henson received honorable mention in the 2006 Nikon Small World competition for his image that he insists captures a fairly routine experiment of a sea-urchin embryo in metaphase, a stage in the life of a cell.

"I chose this photo mainly for its aesthetics but also its significance: the capturing of the embryo's first cell division," explains the Charles A. Dana Professor of Biology and director of the biochemistry & molecular biology program, adding modestly that he has entered and won several contests over the years for images taken through a microscope, known as photomicrographs.

"I've known about this [Nikon contest] for years—it's high profile amongst microscopists."

Founded in 1974 to recognize excellence in photomicrography, the 2006 competition began with 1,700 entries, from which a panel of experts determined the 36 winning images based on their originality, informational content, technical proficiency and visual impact.

Taking the winning photo

Henson's photomicrograph was captured during summer 2004, when he was working at the Marine Biological Laboratory in Woods Hole, Mass. He was assisted in his research there by Christopher Fried '05, now a doctoral student in the Department of Biological Sciences at Carnegie Mellon University.

Specifically, Henson was looking at normal, fertilized sea-urchin embryos and how its chromosomes interacted with microtubules, part of the cell's internal framework that are important for the movement of chromosomes during cell division. He compared these embryos to eggs that had been artificially activated.

To observe these cell processes, Henson used a laser confocal scanning microscope, like one that Dickinson also has, with added organic compounds. His winning image resulted when those compounds were bound to DNA, producing a blue color, and a fluorescent-tagged antibody bound to tubular proteins created the Day-Glo green effect.

The power of the microscope

Like traditional fluorescent microscopes, the confocal instrument picks up the colors in fluorescent tags but with greater sensitivity.

The embryo captured in Henson's winning image was approximately 100 microns—or less than the width of a human hair. Adult sea urchins, spiny, hard-shelled animals that live on the rocky sea floor, are just a few inches in diameter when full grown.

Dickinson's confocal scope, which also gathers data that imaging software can transform into three-dimensional images, was funded by a $325,000 National Science Foundation grant in 2004.

Photos on the road

Henson's photo will be included in a calendar featuring contest winners, and he'll probably hang a copy in his office or lab.

Also the image is scheduled to be part of a national museum tour that includes stops at the New Jersey State Museum in Trenton, N.J., from Nov. 4-Jan. 21, 2007, and at Philadelphia's Wistar Institute, from Jan. 12-March 4, 2007.