Team:TU Delft-Leiden/Human Practices/stakeholders

Discussions with stakeholders

Visit to BioDetection Systems (BDS)

To learn more about the commercial development and application of biosensors, we visited Amsterdam-based biosensor company BioDetection Systems (BDS). Here we met with the Chief Scientific Officer, Mr. Van Der Burg. With him, we discussed the activities of BDS, our project Electrace and the biosensor industry.

The main focus of BDS is their sensing system CALUX. A range of CALUX systems exist, which all work according to a mechanism in which the compound to be detected binds to an intracellular receptor. This complex subsequently binds to a promoter in front of a luciferase gene. The luciferase which is then formed emits light and is in that way used to measure the compound of interest. Compounds which can be detected with CALUX include dioxins and several hormones.

The CALUX system is mainly applied to detect environmental and food contaminations which might be harmful for humans. “We aim to stay close to the physiology of our subject, so in this case this means that we have to use eukaryotic cells, in our case rat cells,” Van Der Burg tells. The use of eukaryotic cells however presents some problems. “For multicellular eukaryotes, there is a big step between contact with the contamination and uptake by a cell, which we have to model and simulate in our experiments. In bacteria you don’t have this problem. Next to that, eukaryotes are less robust and more complex than bacterial cells.” Upon asking why they did not work with bacteria, Van Der Burg tells us: “We are developing a bacterial version of CALUX, but only for usage in areas where bacterial physiology is important, such as soil contamination or antibiotic detection.”

The activities of BDS mainly consist of measuring samples sent by other organizations whit their CALUX system and selling licenses and training to use the system. Their customers include pharmaceutical companies, food companies and (governmental) organizations involved in environmental issues. “We have customers from all over the world. We are currently working on a project in Vietnam to detect dioxins. The concentration of these compounds in Vietnam is far above the health limits as a result of spraying with dioxin-contaminated defoliants.”

Upon being asked about innovations in BDS, Van Der Burg tells us: “We are currently mainly focused on optimizing our CALUX system. We simplify and automate the process of doing assays using our CALUX cells. Although we do not really focus on the detection of novel compounds with new pathways, we are currently trying developing a dioxin sensor for our project in Vietnam. We do this by searching for dioxin receptors which might have arisen in species living in contaminated areas.” However, this is not their usual approach in developing new sensor systems, which consist of extensive literature study and making use of toxicological research.

When we came to discussing Electrace, Van Der Burg reacted very enthusiastic. “Alternative read-outs are very interesting. For light and fluorescence assays you need lots of equipment and devious procedures. For us, this is not really a problem since we do our measurements in the lab, but for a device like yours, which is to be applied in the field, is a really ‘nice trick’.” Also, our plan to create single-use, disposable paper microfluidics strips fascinated him: “That is very interesting; a disposable device is really the thing you need. What would make it even better is if you don’t have to cultivate your bacteria anymore. These costs a lot of time, and maybe even more important, a lot of money.” We further discussed possible (commercial) application of our Electrace system. “Even when a handheld device shows to be unfeasible, there is a lot of potential for you to develop your project in a kit-like setting. This is much easier to sell than a license!”

We told Van Der Burg that we had some concerns about the speed of our system. He told us not to worry about that too much: “Our systems have a response time between 4 and 24 hours. If you really want a fast reaction you should use the translocation of tagged proteins, but this is at the expense of your accuracy.” Furthermore, he gave us some valuable advice: “The specialty of BDS is the measurement of complex mixtures, which is really important for real world applications. If your reporter responds to TNT in a distilled water solution, that is nice, but you should try if it is also possible to sense it in the kind of sample that you will use. In your case this will mean adding TNT to ground water and test it.”