Paul L. Appleton dared to go where few have gone before: into a mouse’s colon. And for his efforts, the researcher from the University of Dundee in the UK won the top prize at Nikon’s annual Small World photography contest.

Appleton captured the pebbly, cobalt blue texture of the cell nuclei of a mouse colon (right) as seen with two-photon fluorescence microscopy. The digital image, magnified 7403, was selected from a pool of 1700 digital images submitted by contestants from an array of scientific fields.

For originality, content, technical proficiency and visual impact, Appleton’s picture won $3000 toward the purchase of Nikon equipment. When not winning photo contests, he researches how cellular changes are regulated and how such changes can contribute to the development of colon cancer.

Rounding out the top three photomicrographs were: Raul M. Gonzalez of the Raul Gonzalez Estudio in Mexico City, Mexico, who took second place for an image of Nostoc cyanobacteria and Diploneis diatom; and Jens Rüchel of the University of Osnabrück in Germany, who earned third place for his portrait of an aquatic worm.

The awards ceremony was held in New York on Sept. 21.