I ran the first microbiology and art workshop at the University of Surrey for over 30 participants last week. Here are the activities and outcomes.
Ehrlich Staining: DIY histology and revealing the oral microbiome
Paul Ehrlich made countless contributions to science in fields as diverse as histology, haematology, immunology, oncology, microbiology and pharmacology. In the course of his investigations Ehrlich came across methylene blue, which he regarded as particularly suitable dye for staining bacteria.
Here I have drawn upon Ehrlich’s early studies on staining bacteria and developed a simple off-the shelf/ DIYBio-staining procedure for bacteria and human cells. It is based on methylene blue which is readily available as a “fish medicine”. The brand I used here is King British Methylene Blue. It works very well as it comes in the bottle, and without the need for any messy preparation. Here participants were asked to spit onto a microscope slide so that saliva could be examined for cheek cells, their nuclei, and the normal oral bacterial flora.
For comparison, below is an unstained saliva sample.
The stained saliva samples were initially observed at 200x magnification (below)
When the stained saliva samples are observed at 1000x magnification far more detail is revealed (below).
Bacterial war-games: visualising bacterial motility, chemotaxis, quorum sensing, swarming and antibiotic production and resistance.
“the microscope discovers, what motions, what tumult, what wars, what pursuits, what stratagems” Samuel Taylor Coleridge
This process was inspired by the boardgames of my childhood, Risk, Campaign and Diplomacy and the like, and also by the inherent properties of bacteria.
Instead of coloured plastic counters, pigmented bacteria constitute the different armies as billions of microscopic soldiers (bacteria) enter into battle. Each colour is a different inoculum of living and pigmented bacteria, with each possessing a different characteristic/ability. The images here are of the initial inoculation (each differently coloured patch represents a seperate bacterial species), and the map after incubation, and after its nature has been changed dramatically as the bacteria became active, grew, and interacted with each other. The red and purple pigmented bacteria are aggressive and swarm to infiltrate certain other species. Blue and yellow adopt a defensive strategies and produce powerful, and yet uncharacterized antibiotics, that kill red to protect their own territory. I can’t help but feel that this map is a metaphor for our own species and wonder, as bacteria predated us in evolutionary terms, whether the traits that we see here are hardwired into our own biology. The battles take place on a layer of the fabric polycotton as this facilitates the movement of the bacteria through its fibres.
The designs made by the participants before incubation.
The designs after incubation (below). During incubation the bacteria move and interact with each other, and dramatically change the participants designs. The outcome reflects our modern understanding of bacteria how they interact and communicate with each other, collaboration, antagonism, swarming, chemotaxis, modes of motility and much much more. I feel that the bacteria contribute to these designs, just as much as the human participants, and that the bacteria are very much coauthors in the works.
Toxic change: bioluminescent bacteria as bioreporters for toxic metals.
When we make physical cash transactions we exchange far more than just metal tokens with monetary value. Carried invisibly at ever transfer, are hundreds of invisible bacteria (see image below) , or the toxic residues of what the coins are made from.
Bioluminescent bacteria naturally produce an ethereal blue light. Healthy cells of these bacteria produce light, those that are damaged are dimmer, and those that are dead are completely dark. Because of this, bioluminescent bacteria are commonly used in laboratories as sensitive and effective monitors of pollution, for testing environmental samples and drinking water for example. In the workshop participants placed coins onto a confluent layer of bioluminescent bacteria. After overnight incubation, obvious zones of darkness are apparent around the coins which means that chemical toxins have diffused from them into the media and killed the bacteria. Most likely this toxic effect is due to the presence of metals like copper and sliver in the coins (see below)
Memories of Failure Externalised: visualising slime mould memories and intelligence
One of the microbes we explored in the workshop was and old favourite, the yellow coloured slime mould Physarum polycephalum. This is a remarkable microorganism that can solve the shortest root through a maze and that also possesses a spatial memory. In essence, as it moves it lays down a layer of slime in a complex 2-dimensional network. When it has explored a region of its environment where there is no food or opportunity, it retracts from this area, but leaves its traces of slime behind. If it encounters these abandoned threads of slime again, it will not re-explore this region, as it knows that it has visited this area before and that there is no reward here. Here participants, like Hansel laid a trail of white pebble, set out a trail of slime mould food (porridge oats) for the organisms to seek out and follow.
I explored a number of ways to represent the participants work and am most pleased with this process that uses a discarded Overhead Projector (OHP) for this. The role of the yellow pigment, that is characteristic of Physarum, is probably to absorb light and to protect the organism from its damaging impact. The images here (below) are of the slime mould as projected via the OHP, and thus after the microorganism has modified and interacted with the light passing through it. I have a strong sense that this process inverts usual microscopic practice, so that instead of a single observer peering down at microscopic worlds through complex series of lenses, the worlds themselves are projected directly into our own macroscopic reality where we can touch and interact with them.
Above the OHP projecting the trail made by the slime mould.
Below are projections of the slime mould, each over a metre in diameter
Park’s Kitchen Agar (PKA): DIY bacteriological growth media
Plate Count Agar (PCA) is a widely used general media for isolated bacteria from many different environments. Park’s Kitchen Agar (PKA) is a novel modification of Plate Count Agar. It can be used for obtaining microbial counts from any environment, and is specifically designed for use in facilities where the availability of chemicals may be restricted by Health and Safety issues or by problems with supply. Unlike any other microbiological agar, it is edible, but consumption is not recommended once it has been inoculated.
The principles of the medium are as follows. The casein present in dried skimmed milk powder provides amino acids and other complex nitrogenous substances that are necessary to support bacterial growth. Marmite, is a form of yeast extract, and primarily supplies the B-complex vitamins need as co-factors. Honey is a natural source of carbohydrates (fructose and glucose) and provides the energy source for growth. The medium can be supplemented with various natural chromogenic compounds that will change colour depending on microbial activity (extract of red cabbage and turmeric are recommended).
This medium wasn’t used for the current workshop but has been widely and successfully used used in many microbiology workshops.