First Place: 2011 Nikon Small World in Motion – Anna Franz

Anna Franz – Ink injection into yolk sac artery of 72 hour-old chick embryo to visualize the beating heart and the vasculature (10x)


University of Oxford
Sir William Dunn School of Pathology


Oxford, UK


Reflected light

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What is the subject matter of your winning entry?

This movie not only demonstrates the power of the heart and the complexity of the vasculature of the chick embryo, but also reflects the beauty of nature’s design.

Can you elaborate on the imaging technique you used to capture this movie?

This technique is relatively easy and quick: A window is cut into an egg to expose the 72h old chick embryo. The embryo is then placed under a stereo microscope. A finely drawn glass capillary needle is filled with India ink and then inserted into an extraembryonic yolk sac artery. Some ink is gently expelled from the needle and the distribution of the ink in the vasculature is followed by time-lapse microscopy. The only challenging part of this technique is the insertion of the needle into the artery without spilling too much ink and without damaging the embryo.

How does this subject matter relate to your work?

I study centriole duplication using Drosophila as a model organism. I am currently doing a PhD in developmental biology studying centriole duplication in Drosophila. In 2010 I took a 6-week course in embryology in Woods Hole where I learnt several techniques used to study embryogenesis in a number of organisms. One of these techniques was the injection of ink into an artery with the aim to visualize the vasculature of the chick embryo.

What first sparked your interest in photomicrography?

When I was a child, my parents got me a simple microscope which I used to look at insects and plants. I became fascinated by microscopy because it reveals the complexity of biological structures most of which our eyes can’t see. Later I decided to studied biology at university where I could combine microscopy with photography.