Our team were keen to use this opportunity to improve education of synthetic biology and raise public awareness of the facts. It was this mind set that led us to develop our ‘Friend in the Dark’, Furri-lux. Furri-lux is a stuffed toy designed to look like a “friendly monster” – he’s the good monster that scares away the bad monsters under the bed!

However, the real magic happens on the inside…


Our bioluminescent bacteria will live in a broth suspension, which will be housed in a vessel made from poly(methyl methacrylate). PMMA was chosen, as it would be sturdy enough so that if it were accidentally dropped or struck, it would prevent the release of the bacteria. It is transparent enough to allow the UV-A rays to reach the bacteria, and for their bioluminescence to shine out.
PMMA is usually distributed with additives in the material that block UV light transmission, among other things, as this is often an undesired quality, however we used a composition that did not contain this, yet still retained its resistance to degradation by UV light.

Adele, using a CAD program called Solidworks, designed and modelled a prototype of Furri-Lux, which was then 3D printed.

Full instructions would be provided with the toy, for adults as well as in the form of bedtime stories for the children, to help them learn how to look after their pet and learn about the science in a way they would understand.

Waste Removal


The main section of the container protrudes from Furri-lux’s chest. Below this is a barrel, which can be turned to reveal a gap, which, in turn, allows the used broth to drop out of the toy, then into the toilet. A ‘kill solution’ of antibacterial solution would be added to ensure the bacteria were no longer viable upon release into the environment, after which they could be flushed away. It was important that the floor of the main section was sloped to allow the broth to drop out as easily as possible. Any crevices would allow broth and bacteria to remain and not be flushed out, which could cause problems.


Disposal of the bacteria was a difficult aspect to design, especially due to our aims of promoting its safe use, however we had to ensure that the procedure would be easy and safe to carry out at home. We considered many different options, such as releasing the bacteria into a container and heating in an oven on a low heat or boiling on the stove, slightly similar to an autoclave, however this is a very wasteful process to conduct at home and carries with it a lot of risks of release. For this reason we opted for disposal via the water system, with the assistance of the kill solution to ensure no interaction is made with the natural environment. The handle of the barrel is removable so that the parents can keep it, thus preventing curious and mischievous children from opening it themselves, causing a release of the bacteria. We have also simulated an antibacterial filter covering the bottom of the container for added safety, as well as reassurance. It is important to note that this is an entirely conceptual design, and no genetically modified bacteria have been released into the environment.



Above the main visualisation chamber is a tube that rises up to Furri-lux’s mouth, where fresh broth can be poured in. New broth would need to be poured in every couple of days, or until the brightness starts to fade – although, if a brighter light is desired, this can be performed more frequently. This also prevents contamination. It is assumed that there would be enough bacteria residing on the sides of the container to repopulate the broth during the day while the child is at nursery or school.


Inside this tube we looked at implementing a one-way valve, so that the fresh broth can easily reach the bacteria, however upon shaking, dropping or inverting, bacteria will not be released. Conceptually, the design of this valve would incorporate a semi-permeable material that meant gas exchange to the container was still possible at all times, without allowing liquid to pass.

First Use


Furri-lux would theoretically come already sterile, with spout bottles of replacement broth (“Monster Food”), and a glycerol stock of replacement bacteria to be kept in the freezer. Each broth bottle would hold enough broth to half fill the main compartment, leaving room for the bacteria to be sufficiently ventilated. Upon first opening the toy, one of the broth bottles would need to be inoculated with bacteria from the glycerol stocks – using toothpicks and gloves – and poured into the toy.


It is important that contamination does not occur during inoculation of the initial broth bottle. Wearing gloves would be recommended for this task, along with the use of sterile toothpicks, both of which could be provided.


In the event that the container became contaminated with a wild type bacteria from the environment, the bioluminescent bacteria would be overwhelmingly out competed, resulting in no glow. In this instance, the contents of the toy would need to be emptied and killed as usual, however, the inside of the container would also need to be rinsed with the kill solution through the opening at the mouth, allowing Furri-Lux to be decontaminated and any remaining cells to be rinsed away. This process should be repeated again with water to ensure there was no antibacterial solution left behind preventing the bacteria from growing again. After this, the same steps that were taken upon first use of the toy would be conducted again to repopulate the container.

Future Considerations

In hindsight, it was thought the toy may be slightly too large to fit comfortably on a child’s windowsill. If mass production were to be considered, a scaled down version of the toy would not affect its functionality as a pet, a light source or an educational tool, but would mean it would be more comfortable on a small ledge, as well as less material being consumed in its production and less broth being needed to fill it, bringing down costs. The larger model is, however, better for demonstrating and displaying the different components.

Alternative Products

Sea monkey

“Sea Monkeys” were a very popular novelty pet during the 50s and 60s after their invention by Harold von Braunhut in 1957, and still sell well today. They are a hybrid of different brine shrimp within the Artemia species, named Artemia NYOS, which can exist as eggs in suspended animation for an extremely long time. Once poured into purified salt water they hatch “instantly”.


Sea Monkeys are large enough to see swimming around once they are fully grown, unlike our bacteria which would remain too small to be visible to the naked eye. In addition they do not pose any risk to the environment in the event of release, which is something that is theoretically true of our bacteria, however the small risk of mutation or other adverse effect will always be present.


Sea Monkeys do not require a UVA source, however they do not glow in the dark, which gives an extra element of functionality to our toy.

So yes… Sea Monkeys have a considerable degree of advantage over our product in terms of ease of use and maintenance. There is also the compromise between whether they glow or are visible individually to the naked eye… but what if we combined them? A future iGEM team idea could be to create glow in the dark Sea Monkeys…!


Bower Building, Wilkins Teaching Laboratory
University of Glasgow
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