Gram Negative Clay

Title: Gram Positive Clay

Artist: Michael Kaden-Hoffmann

Media: Polymer Clay

Scientific Concept: One major way the bacteria are categorizes is by how they react to a gram stain. The two categories resulting from a gram stain are pink gram-negative bacteria and purple gram-positive bacteria. The reason for this color difference is difference in the make up and thickness of the cell wall of the bacteria. Gram-positive bacteria have a thick layer of peptidoglycan that surrounds the cell membrane and traps the purple, crystal violet stain in the cell. Gram negatives have lipopolysaccharide layer and a much smaller peptidoglycan layer surrounding the cell membrane and thus the crystal violet stain is washed out and only shows the pink safranin stain remains.

Artist Concept: I want to create a piece that showed what a gram-positive bacteria looks like up close as that was the type of bacteria that I had for my term project. So to do this, I made half a coccus gram-positive cell out of clay. In the middle I made the cytoplasm purple to show the stain. In the cytoplasm I included ribosomes, a plasmid, and supercoiled circular DNA. Surrounding the cytoplasm I made the lipid bilayer with membrane proteins. Around the bilayer I made the thick peptidoglycan layer with teichoic acid that gives it its negative charge as well as a few proteins. In a normal cell there is some space between the cell membrane and the peptidoglycan layer, however I was not able to incorporate that. Other then that and the size the only other inconsistence with real bacteria is that my peptidoglycan layer is thinner then the real one, and the reason for this was that I ran out of clay. Banana (made by nature) for scale.