Are you Richard Klemm?

Claim your profile

Publications (19)8.01 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A central method in a standard biochemical laboratory is represented by the polymerase chain reaction (PCR), therefore many attempts have been performed so far to implement this technique in lab-on-a-chip (LOC) devices. PCR is an ideal candidate for miniaturization because of a reduction of assay time and decreased costs for expensive bio-chemicals. In case of the "classical" PCR, detection is done by identification of DNA fragments electrophoretically separated in agarose gels. This method is meanwhile frequently replaced by the so-called Real-Time-PCR because here the exponential increase of amplificates can be observed directly by measurement of DNA interacting fluorescent dyes. Two main methods for on-chip PCRs are available: traditional "batch" PCR in chambers on a chip using thermal cycling, requiring about 30 minutes for a typical PCR protocol and continuous-flow PCR, where the liquid is guided over stationary temperature zones. In the latter case, the PCR protocol can be as fast as 5 minutes. In the presented work, a proof of concept is demonstrated for a real-time-detection of PCR products in microfluidic systems.
    02/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aim of the paper is the demonstration of a paradigm shift in shape, color and spectral measurements in industry, biology and medicine as well as in measurement science, education and training. Laboratory applications will be supplemented and replaced by innovative in-field and point-of-care applications. Innovative functional modules are smartphones and/or smartpads supplemented by additional hardware apps and software apps. Specific examples are given for numerous practical applications concerning optodigital methods. The methodological classification distinguishes between different levels for combinations of hardware apps (hwapps) and software apps (swapps) with smartphones and/or smartpads. These methods are fundamental enablers for the transformation from conventional stationary working places in industry, biology, medicine plus science, education and training towards innovative mobile working places with in-field and point-of-care characteristics as well as mobile open online courses MOOCs. The innovative approach opens so far untapped enormous markets for measurement science and engineering. These working conditions will be very common due to their convenience, reliability and affordability. The fundamental enablers are smartphones and/or smartpads. A highly visible advantage of smartphones and/or smartpads is the huge number of their distribution, their worldwide connectivity via Internet and cloud services and the experienced capabilities of their users for practical operations. Young people are becoming the pioneers.
    Journal of Physics Conference Series 09/2013; 459(1):2010-.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aim of the paper is the orientation of research and development on a completely new approach to innovative in-field and point of care diagnostics in industry, biology and medicine. Central functional modules are smartphones and/or smart pads supplemented by additional hardware apps and software apps. Specific examples are given for numerous practical applications concerning optodigital instrumentations. The methodical classification distinguishes between different levels for combination of hardware apps (hwapps) and software apps (swapps) with smartphones and/or smartpads. These methods are fundamental enablers for the transformation from stationary conventional laboratory diagnostics into mobile innovative in-field and point of care diagnostics. The innovative approach opens so far untapped enormous markets due to the convenience, reliability and affordability of smartphone and/or smartpad instruments. A highly visible advantage of smartphones and/or smartpads is the huge number of their distribution, their worldwide connectivity via cloud services and the experienced capability of their users for practical operations.
    Proc SPIE 03/2013;
  • Biomedizinische Technik/Biomedical Engineering 09/2012; · 1.16 Impact Factor
  • Biomedizinische Technik/Biomedical Engineering 08/2012; · 1.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microfluidics has proven to be a very effective technology for the identification of biological and chemical analytes in a CBRNE scenario. As it will be shown in the following, the required steps of those analytical processes are manifold making the development of an integrated microfluidic device a complicated project with a high level of technological risk, because all necessary analytical processes have to be implemented into a single device. The implementation is initiated by a dissection of the biochemical workflow into mandatory bio-analytical steps and the resulting protocol for each of those steps is translated into an appropriate design of a chip-based unit. In this report, examples for such chipbased functional modules are given. In addition, examples for a merging of positively tested modules into an integrated chip are shown and, finally, representatives for a smooth interaction between outer world, microfluidic chip, and chip driving instrument are presented.
    Proc SPIE 05/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The translation of bio-analytical processes into an automatically functioning microfluidic platform is an attractive task for several reasons. However, due to the complexity of the resulting integrated device covering various process steps like lysis, DNA extraction and purification, continuous-flow PCR and detection etc., these single functional units have to be carefully developed and evaluated in a first step, thus allowing a functional verification prior to final device integration. All the modules as well as the final integrated device have to be manufactured using scalable industrial manufacturing methods, namely injection molding, in order to facilitate commercialization The final integrated device should have a footprint such as SBS-titerplate format, which is generally excepted by the user. For optimal space utilization, microfluidic structures should be on both the top and the bottom side of the device connected with through-holes. The device described in this report is a pathogen DNA analysis example realising all the above prerequisites. Sample is introduced through a Luer-connector in one corner. DNA is extracted in a chamber, which is filled with magnetic beads. All necessary liquid reagents are stored in 500μl modules which are clipped onto the chip. The sample is aliquoted into 8 tracks, liquefies the PCR-reagents which are stored in lyophilized form in small chambers and runs through a meandering channel, in which continuous-flow PCR takes place. The samples are then transferred to the top of the chip and run back to the detection zone where a fluorescence detection of the PCR-products takes place before flowing into waste. As in the device an 8-plex detection is targeted, the spacing of the microchannels after qPCR had to be very narrow in order to have all channels within the field of vision of the detection system.
    Proc SPIE 05/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: There is a need to design an integrated microfluidic platform as simple and lean as possible in order to meet the requirements for a miniaturized system. Magnetic particles show a great versatility in performing several of the functions necessary in many microfluidic assays. We therefore have developed a compact portable system to perform magneticbead- based sample preparation steps in a chip such as DNA-extraction or particle-enhanced mixing of reagents. A central application in a standard biochemical/biological/medical laboratory is represented by PCR. The execution of a cyclic heating profile during PCR is a considerable stress for chip and liquid inside the chip because evaporation and uncontrolled condensation or unintended motion of the PCR solution. One strategy to overcome this problem consists of the implementation of valves flanking a stationary PCR in appropriate incubation cavities. In addition to the well-known elastomeric membrane valves, wax-valves mechanical turning or rotary valves flanking the PCR chamber, we present in this paper the use of clustered magnetic particles as blocking valves for such reaction chambers. We report on the capability of assembled magnetic particles to act as rather simple configurated valves during a PCR typical temperature regime. These novel valves efficiently withstand 1.5 bar pressure, prevent loss of aqueous liquid inside the reaction chamber via evaporation or bubble formation, and do not express adverse effects on any biological reaction inside the chip-based PCR cavity. The latter properties have been proven by a set of different PCRs performed in chip-based cavities.
    Proc SPIE 02/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: For complex biological or diagnostic assays, the development of an integrated microfluidic device can be difficult and error-prone. For this reason, a modular approach, using individual microfluidic functional modules for the different process steps, can be advantageous. However often the interconnection of the modules proves to be tedious and the peripheral instrumentation to drive the various modules is cumbersome and of large size. For this reason, we have developed an integrated instrument platform which has generic functionalities such as valves and pumps, heating zones for continuous-flow PCR, moveable magnets for bead-based assays and an optical detection unit build into the instrument. The instrument holds a titerplate-sized carrier in which up to four microscopy-slide sized microfluidic modules can be clipped in. This allows for developing and optimizing individual assay steps without the need to modify the instrument or generate a completely new microfluidic cartridge. As a proof-of-concept, the automated sample processing of liquor or blood culture in microfluidic structures for detection of currently occuring Neisseria meningitidis strains was carried out. This assay involves the extraction of bacterial DNA, the fluorescent labeling, amplification using PCR as well as the hybridization of the DNA molecules in three-dimensional capture sites spotted into a microchannel. To define the assay sensitivity, chip modules were tested with bacteria spiked samples of different origins and results were controlled by conventional techniques. For liquor or blood culture, the presence of 200 bacteria was detected within 1 hour.
    Proc SPIE 02/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper we demonstrate the development of an integrated lab-on-a-chip system for the point-of-care diagnostics of Coeliac disease. A two-step approach is used, using two different microfluidic chips with identical footprint and functional landscape, one for the analysis of the genetic predisposition using human leukocyte antigen typing, the second for a serology assay. Emphasis has been put on using a seamless technology path from prototyping to final device manufacture in order to allow an upscaling of production volumes without a chance in production technology. Therefore, injection molding has been extensively used, however using standard formats allowing the use of family tools in order to reduce the cost of manufacturing.
    Proc SPIE 02/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Taking advantage of microfluidics technology, a Lab-on-Chip system was developed offering the possibility of performing HLA (Human Leukocyte Antigen) typing to test genetic predisposition to coeliac disease and measure the level of immunodeficiency at the point-of-care. These analysis procedures are implemented on two different microfluidic cartridges, both having identical interfacial connections to the identical automated instrument. In order to assess the concentration of the targeted analytes in human blood, finger prick samples are processed to either extract genomic DNA carrying the coeliac disease gene or blood plasma containing the disease specific antibodies. We present here the different microfluidic modules integrated in a common platform, capable of automated sample preparation and analyte detection. In summary, this new microfluidic approach will dramatically reduce the costs of materials (polymer for the disposable chips and minute amount of bio-reagents) and minimize the time for analysis down to less than 20 minutes. In comparison to the state of the art detection of coeliac disease this work represents a tremendous improvement for the patient's quality of live and will significantly reduce the cost burden on the health care system.
    Proc SPIE 02/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: A microsystem integrating electrochemical detection for the simultaneous detection of protein markers of breast cancer is reported. The microfluidic platform was realized by high precision milling of polycarbonate sheets and features two well distinguishable sections: a detection zone incorporating the electrode arrays and the fluid storage part. The detection area is divided into separate microfluidic chambers addressing selected electrodes for the measurement of samples and calibrators. The fluidic storage part of the platform consists of five reservoirs to store the reagents and sample, which are interfaced by septa. These reservoirs have the appropriate volume to run a single assay per cartridge and are manually filled. The liquids from the reservoirs are actuated by applying a positive air pressure (i.e.via a programmable syringe pump) through the septa and are driven to the detection zone via two turning valves. The application of the realised platform in the individual and simultaneous electrochemical detection of proteic cancer markers with very low detection limits are demonstrated. The microsystem has also been validated using real patient serum samples and excellent correlation with ELISA results obtained.
    Lab on a Chip 02/2011; 11(4):625-31. · 5.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lab-on-a-chip systems are seen as a very promising approach for a decentralized continuous pathogen monitoring technology. In this paper, we present the development of a fully integrated device for the multiplexed nucleic-acid based identification of pathogens. Due to the complexity of such a fully integrated device, in a first development step, functional modules for the various process steps like lysis, DNA extraction and purification, continuous-flow PCR and detection have been developed and evaluated, allowing a functional verification prior to integration. All the modules as well as the final integrated device have been manufactured using scaleable industrial manufacturing methods, namely injection molding in order to facilitate commercialization.
    Proc SPIE 02/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present a compact portable chip-based capillary electrophoresis system that employs capacitively coupled contactless conductivity detection (C4D) operating at 4 MHz as an alternative detection method compared to the commonly used optical detection based on laser-induced fluorescence. Emphasis was put on system integration and industrial manufacturing technologies for the system. Therefore, the disposable chip for this system is fabricated out of PMMA using injection molding; the electrodes are screen-printed or thin-film electrodes. The system is designed for the measurement of small ionic species like Li+, Na+, K+, SO42- or NO3- typically present in foods like milk and mineral water as well as acids e.g. in wine.
    Proc SPIE 05/2009;
  • [Show abstract] [Hide abstract]
    ABSTRACT: A universal microfluidic platform as a multisensor device for cancer diagnostics, developed within the framework of the EU project SmartHEALTH [1], will be presented. Based on a standardization concept, a microfluidic platform was realized that contains various functional modules in order to allow in its final setup to run a complete diagnostic assay on a chip starting with sample preparation to a final detection via a sensor array. A twofold concept was pursued for the development and standardization: On the one hand, a standard footprint with defined areas for special functional elements was chosen, on the other hand a toolbox-approach [2] was used whereas in a first instance different functional fluidic modules were realized, evaluated and afterwards integrated into the microfluidic multisensor platform. One main characteristic of the platform is that different kind of sensors can be used with the same fluidic chip. For the read-out and fluidic control of the chip, common fluidic interfaces to the instrument were defined. This microfluidic consumable is a hybrid system consisting of a polymer component with an integrated sensor, reagent storage on chip, integrated valves and metering elements.
    Proc SPIE 05/2009;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The overall aim is the realization of a reliable, ultrafast, and portable tool for the identification of B-agents at the point of interest. PCR is the method to be used for the doubtless identification of e.g. bacteria, and viruses. Miniaturization is the way to include the overall analysis process, from sample preparation to detection, on a microtiterplate-sized consumable device and to allow to carry out the analysis without the need for an equipped biological laboratory. The novel PCR concept with constant temperature zones allows also for the instrument to become portable, due to much reduced power consumption since no thermocycling is necessary. This paper focuses on the overall concept to implement the biological reactions for the analysis on-chip, the methods of sample preparation on-chip, and the results of the ultrafast PCR with B-agents on-chip, as well as the basic instrument.
    Proc SPIE 05/2009;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Continuous-flow PCR has proven to be a powerful method for the amplification of genetic material due to its high speed and the possibility to perform amplicon detection and separation on-chip. A unique possibility of this method is the simultaneous amplification of several samples within a single chip by sample stacking, either having identical samples in several sample plugs separated by e.g. a mineral oil or using different samples in each sample plug. We have demonstrated the viability of sample stacking with a commercially available continuous-flow PCR system with a variety of protocols and samples. Further integration steps like thermal lysis and on-chip lyophilisate storage have been performed, with subsequent successful PCR. Chip modules for DNA extraction either with magnetic beads or membrane filters have been developed.
    Proc SPIE 02/2009;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a compact portable chip-based capillary electrophoresis system that employs capacitively coupled contactless conductivity detection (C4D) operating at 4 MHz as an alternative detection method compared to the commonly used optical detection employing laser-induced fluorescence. The disposable chip for this system is fabricated out of PMMA using injection molding; the electrodes are screen-printed or thin-film electrodes. The system allows the measurement of small ions like Li, Na, K typically present in foodstuff like milk and mineral water as well as acids in wine.
    Proc SPIE 01/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PCR is the most commonly used method to identify DNA segments. Several methods have been used to miniaturize PCR and perform it in a microfluidic chip. A unique approach is the continuous-flow PCR, where the conventional thermocycling is replaced by pumping the sample through a channel which meanders over stationary temperature zones, allowing fast temperature changes in the sample due to the low thermal mass as well as a continuous production of PCR products. In this paper we present a system comprising a polymer microfluidic chip, a thermocycler unit and the protocols necessary to perform fast continuous-flow PCR including experimental results in comparison with a conventional PCR system.
    Proc SPIE 01/2007;