"The biggest challenge comes from the future user’s wish for shorter development time and availability"

Interview with Dr. Thomas Henkel, German Leibniz Institute of Photonic Technologies, Jena

Lab-on-a-chip systems automate laboratory procedures, speed up analyses and improve data quality. These three aspects are important and valuable when a lot of different substances need to be tested in a standardized, efficient procedure – for example in the search for new agents.


Photo: Laboratory work

Lab-on-a-chip systems make otherwise long and tedious laboratory work easier; © panthermedia.net/Radu Razvan

COMPAMED.de talked to Dr. Thomas Henkel from the German Leibniz Institute of Photonic Technologies in Jena about advantages the chips provide, the use of photonic technologies and the computer-assisted optimization of the systems that heavily reduces development time.

COMPAMED.de: Dr. Henkel, what role do biomicrosystems generally play in simplifying laboratory processes?

Thomas Henkel: Along with the progressive development of new laboratory procedures and detection principles of bioanalysis, demands on technical equipment of research laboratories and scientific qualifications of staff are increasing. In addition to the increase in analytic capacity and a reduction in analysis time, the automation of laboratory procedures also contributes to ensuring quality and reproducibility of measurement data.

The transfer of laboratory procedures to lab-on-a-chip systems addresses these aspects. Lab-on-a-chip systems are specifically developed and applied for the speedy, automated implementation of specified laboratory procedures. As benchtop systems or equipment components, they do not require a special laboratory infrastructure. One advantage that should not be underestimated is the savings in materials and reagents thanks to miniaturization. Particularly with the use of expensive substances or substances with limited availability, respectively, this approach makes the feasibility of these tests possible in the first place. However, the biggest advantage is in the improvement of the quality and validity of achievable test readings with these systems and the thus derived scientific findings and data.
Photo: bacteria; Copyright: panthermedia.net/eraxion

"There are also benefits for the high-throughput screening of new antimicrobial agents": Lab-on-a-chip systems make standardized test series with a lot of different samples possible; © panthermedia.net/eraxion

COMPAMED.de: You design biochips to search for new antimicrobial agents. How do these tests work?

Henkel: Based on patented techniques, we focus on the implementation of lab-on-a-chip systems for cell-based and microbial assays. In doing so, the original sample is divided into a multitude of sample drops with variable compositions of effectors and auxiliary reagents and subsequently undergoes the analytical procedure. Due to the fine and systematic graduation of concentration in the drops, you can generate many thousands of single tests to measure dose-response characteristics from one 200 µl individual sample.

This approach has excellent potential to research the biological activity of new active agents, but also the mode of action of known materials. There are also benefits for the high-throughput screening of new antimicrobial agents. To do this, a sample with unknown microorganisms that is obtained from soil samples for example, is divided into drops to where each drop is inoculated with one germ only. After incubation, a so-called microorganism reporter is being added. If it is being inhibited in its growth, you can then assume that an antimicrobial active substance was cultivated in this drop. After extracting the drop, the strain can inoculate agar plates and be used for further research.

COMPAMED.de: How do you use optical technologies for analysis?

Henkel: As fast, contactless and non-destructive measurement methods, optical detection technologies offer a broad range of methods to readout data from lap-on-a-chip systems. Spectral imaging combined with automated image processing provides the foundation for this. Additionally, spectroscopic procedures are being utilized. Raman spectroscopy in particular offers brand-new possibilities due to its high information density of gained spectra and the application with aqueous solutions.

COMPAMED.de: What are the requirements for materials and construction of your chips?

Henkel: Generally, chip systems are task-specifically developed and prepared for a process specified by the user. The future user also specifies the material properties. For spectroscopic detection procedures, the components are prepared from high optical quality glass or quartz glass, respectively. Disposables can be prepared at low-cost and in large quantities using mass production processes, such as the manufacturing technology of CD-ROMs and DVDs for instance.
Photo: Desktop

"Similar to the electronic design automation process used in microelectronics, the target system is first designed as a simulation model and evaluated in silico": The simulation reduces the time to test and optimize the system to a few seconds;
© panthermedia.net/orcearo

COMPAMED.de: What requirements do users from (bio-) medical research have for your chip systems?

Henkel: The biggest challenge comes from the future user’s wish for shorter development time and availability. An obstacle for this is the time-consuming first draft as well as the technologically sophisticated production using microsystems technology. Sometimes iterative design optimization with several cycles of optimization might test the patience of the user.

We pursue strategies for the interactive model-based design of integrated lab-on-a-chip systems for a problem-solution approach. Similar to the electronic design automation process used in microelectronics, the target system is first designed as a simulation model and evaluated in silico.

With the simulation software our group developed, a complete system simulation for a drop-based lab-on-a-chip system only takes several seconds. In the run-up to the project implementation, you can therefore interactively and jointly with the user optimize the target system to where it meets his/her specifications. We hope to gain a significant reduction in development time and availability from this approach and also a reduction in development risk. The prerequisite for the application of this procedure is the availability of mathematical models for the microfluidic functional components that are to be applied. The focus of our fundamental research activities is their research and exploration.

COMPAMED.de: Do you see specific trends that will prevail in terms of design and engineering of chips for (bio-) medical purposes?

Henkel: The variety of technological approaches for chip preparation, the many possibilities in microfluidics as well as the range of application scenarios makes room to establish many different kinds of microfluidic platforms with different performance features. Aside from drop-based microfluidics, we should also mention centrifugal microfluidics, lateral flow assays, DNA and protein microarray technology, microreaction technology platforms or the possibilities that arise from the application of rapid prototyping techniques such as 3D printing for instance for the fast preparation of prototypes of lab-on-a-chip components. Depending on the requirement profile, the goal is to identify the optimal platform for the respective task in the forefront of chip development.
Photo: Timo Roth; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Timo Roth and translated by Elena O'Meara.