Horseshoe crab blood: Old, new, and blue

Purpose

Horseshoe crab blood is the main ingredient for the Limulus amebocyte lysate (LAL) test, which is used to screen for endotoxin contamination in the biomedical industry.

The goal of this infographic was to explore the LAL test more deeply, from a background on endotoxins and the horseshoe crab immune response, to a closer look at the cellular and molecular mechanisms that makes the LAL test able to detect even the slightest presence of endotoxins. Lastly, the infographic explores the significance of blood harvesting on wild horseshoe crab populations, and alternative solutions.

Audience

Client

Science magazine readers

Intended format

Tools used

Science magazine spread

​Procreate, ChimeraX, VMD, Autodesk Maya, Adobe Illustrator, Adobe Photoshop

Derek Ng, University of Toronto

Thumbnails

The LAL test is complex and there was a lot of information to cover, so an ongoing challenge of this spread was layout. I wanted to establish a hierarchy of information, but make the spread remain as approachable and intuitive as possible.

Molecular research

After referencing the RCSB Protein Data Bank (RCSB PDB), I found a PDB structure for Factor C on Alphafold. I found LPS and a gram-negative cell membrane on the CHARMM database. I initially used 3D Protein Imager to visualize the structures.

Using Uniprot annotations, I isolated the Factor C residues involved in LPS detection using VMD and ChimeraX. I also checked simulations of Factor C interactions with the cell membrane to determine its approximate placement.

Layout considerations

Now having a better understanding of the molecules, I adjusted my layout accordingly.

Molecular modelling

After researching Factor C’s relationship to the cell membrane and cleaning the molecule with ChimeraX and VMD, I moved Factor C and the lipid bilayer into Maya.

Molecule rendering

After testing a few colour options, I rendered the Factor C reaction in Maya, adjusted colours in Photoshop, and then cleaned things up in Procreate. I experimented with a darker blue background to simulate the blue blood hemolymph outside of the cell, but I ultimately went with a lighter colour scheme.

Prefinal and final

I used Adobe Illustrator for final layout, icons, and typesetting. I also drew a horseshoe crab spot illustration, and eventually a beach of horseshoe crabs, in Procreate.

Interested in working together? Let’s talk about it.

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