I was contacted by Dr Hannah Pendergraff on behalf of a team of scientists who had completed a project for the Roche Innovation Centre Copenhagen (RICC).
The team had worked on a paper that had been accepted by the Nucleic Acid Therapeutics journal to be published in their next issue. They had also been offered the prestigious opportunity to submit an image that represented their work to be used on the cover.
Hannah requested an illustration that was in black and white, felt elegant and looked semi realistic. The team specified that they would like to include a magnifying glass to show a close up of the nucleus of a cell and internal interactions of oligonucleotides with proteins, and for there to be an abacus present to represent quantification.
I was supplied with an example bright-field microscopy image of the HeLa cell line that they had used for the work and a close up fluorescent image of DAPI stained nuclei to highlight the internal structures and textures that they were keen to illustrate.
In their publication Hannah and her team outline a novel three-step methodology for the quantification of exogenous oligonucleotide delivery within distinct sub-cellular compartments.
This technique is particularly exciting due to the fact that it does not utilise fluorescent markers, which are the current gold standard for quantifying oligonucleotide movement. The presence of these markers has been shown to influence cellular dynamics and therefore a technique devoid of such interference should provide a much more reliable insight into the movement of therapeutic oligonucleotides on their own.
Furthermore, this new methodology uses relatively simple and accessible techniques allowing for its immediate implementation in most laboratories.
"Nuclear and Cytoplasmatic Quantification of Unconjugated, Label-Free Locked Nucleic Acid Oligonucleotides" Hannah Pendergraff, Steffen Schmidt, Jonas Vikeså, Christian Weile, Charlotte Øverup, Marie W. Lindholm, and Troels Koch. Nucleic Acid Therapeutics.
I presented the team with several compositional options for the layout of the cover image.
Layout 1- Contained the basic elements described in the brief
Layout 2 - The magnifying glass was replaced with a simple box zoom to better demonstrate the fact that no microscopy was not necessary for this technique.
Layout 3 - Showed cells coming towards the front of the image as another option to zoom in without a magnifying glass.
Layout 4 - Adds three elements of labware into the background of the image to highlight the three steps of the methodology used as well as labelling of each cell with a numerical figure to highlight that this can be a highly automated process unlike current approaches.
Layout 5 and 6 - are just some combinations of the above
The team provided some great feedback on these compositions and overall decided to go with Layout 1.
In order to create the 'elegant' feel that Hannah was after I wanted to illustrate HeLa cells that looked as if they were made out of glass. I was inspired by the work of Luke Jerram and his glass microbe structures. I used images of glasswork as references for the texture and highlights of the cells and for interpreting how the internal organelles would be seen through the cell surface.
As I have first hand experience of HeLa cell culture and microscopy I am familiar with the morphology of the cells and the complex structures within the nuclei that I wanted to include. I added several more cells into the background of the image to create a flowing feeling reminiscent of the smooth stream of cells that would be taken up by a flow cytometry machine. This gives the image a more pleasing, dynamic feel.
Following feedback from the team, the abacus design was simplified from the original concept work and additional oligonucleotides were included in the cytoplasm of the cell. As described in the publication some of these oligonucleotides were encapsulated by cytoplasmic endosomes.
The final feedback from the team was to reduce the size of the abacus so that there was no overlap with the magnifying glass, and to change the 'colours' of each row of beads to reflect a more realistic item.
Taking on the feedback from the team I then finalised the piece with a lot more detailing on all of the elements.
In order to maintain the traditional feel I used a photo of an old-fashioned style magnifying glass as a reference for the shading and reflections on this, including some tarnishing of the metalwork. I created a wood effect on the frame of the abacus and deepened the contrast and shading on the beads to make them pop.
I added more oligonucleotide structures to the magnified cell and increased the depth of cell by darkening the smaller structures into the cytoplasm.
More organelles were added to the background cells and the contrast of the glass effects increased. I added a smooth highlight behind the cells to emphasize their sweeping motion across the image.
Finally, I added some glassy reflections and highlights to the cells and magnifying glass to complete the piece.
Vol 30 issue 1 of Nucleic Acid Therapeutics was published online 29 Jan 2020