3D model of Escherichia coli. Model size: 2 cm cell diameter; 4 cm length. The number “11” is also printed on the model which enable the participant to match bacteria and name in the context of multiple bacteria printed at the same scale. A scale of 20,000× was chosen to (1) enhance visual and tactile aspects of printed-model handling and (2) enable comparison of size and shape within the mammalian microbiome, with a focus on the human microbiome.

For printing strategy details, see manuscript at https://doi.org/10.1525/abt.2021.83.3.188