Dynamically Tunable Color of Cells in Squid Skin (selected by the editors as the cover image for my research article in JBC...
Resembling Monet's "Water lilies" in micro-scale, a wave of color ripples through the cells in a squid's skin as they’re activated to progressively reflect colors of the rainbow. Proteins in the cell’s nano-scale reflective structures drive these “biophotonic” changes for camouflage or signaling.
I used a regular microscope with a simple camera attached to image light reflected from the squid skin. After adding a drop of the neurotransmitter, acetylcholine, to a spot on the sample (corresponding to the top of the image), I waited about 30 seconds until the wave of activated color lit-up the entire sample before clicking the shutter. The squid can selectively tune these cells to reflect any color, with the process being quickly reversible and repeatedly cyclable. (Each object shown is a single cell, ca. 10 micrometers long; the dark spot in the center of each cell corresponds to the position of the nucleus.) This image was selected by the editors as the cover image for the Journal of Biological Chemistry, (June 12, 2015) in which my research article was published.