Cellock Holmes - A Case of Identity

• 2D Biosensor
• REACh Construct
• Galectin-3
• WatsOn

"What is living on the table in front of you?" seems to be an easy question to answer: microoganisms. However, "Which microorganisms are living on the table in front of you?" is not such a trivial question anymore, especially in environments where you only want to have a non-pathogenic microflora, or no microorganisms at all, such as lab spaces or health care institutions.

Our project Cellock Holmes solves this case of identy.

Cellock Holmes encompasses our 2D biosensing technology with which we want to enable detection of bacteria on solid surfaces. When developing Cellock Holmes, a main goal was to overcome shortcomings of excisting detection methods such as high cost, heavy and sensitive equipment, complicated handling and long detection times. Instead of inventing a mainly fancy concept for detecting bacteria, we wanted to create a biosensor that is

• fast
• inexpensive
• open source
• mobile
• easy to handle

As a proof-of-concept for Cellock Holmes we decided to detect the bacterium Pseudomonas aeruginosa. This opportunistic bacterium mainly infects patients with open wounds and burns as well as immuneodeficient people. P. aeruginosa cells use quorum sensing to communicate with each other, and in doing so secrete autoinducers into their environment. Using Synthetic Biology, our team engineered sensor cells, so-called Cellocks, that are able to detect said autoinducers and to elicit a fluorescence signal. Furthermore, the response time of our sensor cells is sped up, through the use of our special REACh construct.

So far Cellocks are able to detect P. aeruginosa only, however, due to the modular composition of our genetic device, it is possible to engineer Cellocks in a way that they are able to detect other bacteria's autoinducers. Even more flexibility would be introduced using our alternative molecular approach using Galectin-3.

Hand in hand with the biological side of our project, our IT crew built the measurement device WatsOn that is able to read and analyze the fluorescent signal. Since we want to make our technology available for everybody, we publish construction manuals and technical details of our device.

To learn more about the different parts of our 2D biosensor, click on the respective panels on the right.

The OD/F Device - A Project Spin-Off

• OD/F Device

Originally planned to be used as our own measurement device in the Interlab Study, our IT division developed our OD/F Device. This device can measure optical density and fluorescence of a liquid sample. It is used in the same way as a regular spectrophotometer: A plastic cuvette is filled with sample solution and inserted into the device. The values of optical density and fluorescence are subsequently displayed to the user.

The target group for our device are low-budget institutions such as schools, community labs and the bio-hacker scene. The OD/F device is designed in accordance with the open source principle, and all technical details and construction manuals are published on our wiki.