TY - JOUR A1 - Bauer, Christian G. A1 - Eremenko, A. V. A1 - Ehrentreich-Förster, Eva A1 - Bier, Frank Fabian A1 - Makower, Alexander A1 - Halsall, H. B. A1 - Heineman, W. R. A1 - Scheller, Frieder W. T1 - Zeptomole-detecting biosensor for alkaline phosphatase in an electroche mical immunoassay for 2,4- dichlorophenoacetic acid Y1 - 1996 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Schubert, Florian A1 - Bier, Frank Fabian T1 - Vom Biosensor zur Nanobiotechnologie Y1 - 1995 ER - TY - JOUR A1 - Warmt, Christian A1 - Fenzel, Carolin Kornelia A1 - Henkel, Jörg A1 - Bier, Frank Fabian T1 - Using Cy5-dUTP labelling of RPA-amplicons with downstream microarray analysis for the detection of antibiotic resistance genes JF - Scientific reports N2 - In this report we describe Cy5-dUTP labelling of recombinase-polymerase-amplification (RPA) products directly during the amplification process for the first time. Nucleic acid amplification techniques, especially polymerase-chain-reaction as well as various isothermal amplification methods such as RPA, becomes a promising tool in the detection of pathogens and target specific genes. Actually, RPA even provides more advantages. This isothermal method got popular in point of care diagnostics because of its speed and sensitivity but requires pre-labelled primer or probes for a following detection of the amplicons. To overcome this disadvantages, we performed an labelling of RPA-amplicons with Cy5-dUTP without the need of pre-labelled primers. The amplification results of various multiple antibiotic resistance genes indicating great potential as a flexible and promising tool with high specific and sensitive detection capabilities of the target genes. After the determination of an appropriate rate of 1% Cy5-dUTP and 99% unlabelled dTTP we were able to detect the bla(CTX-M15) gene in less than 1.6E-03 ng genomic DNA corresponding to approximately 200 cfu of Escherichia coli cells in only 40 min amplification time. Y1 - 2021 U6 - https://doi.org/10.1038/s41598-021-99774-z SN - 2045-2322 VL - 11 IS - 1 PB - Macmillan Publishers Limited, part of Springer Nature CY - [London] ER - TY - JOUR A1 - Bier, Frank Fabian A1 - Ehrentreich-Förster, Eva A1 - Scheller, Frieder W. A1 - Makower, Alexander A1 - Eremenko, A. V. A1 - Wollenberger, Ursula A1 - Bauer, Christian G. A1 - Pfeiffer, Dorothea A1 - Micheel, Burkhard T1 - Ultrasensitive biosensors Y1 - 1996 ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Bier, Frank Fabian T1 - Trends in der Bioanalytik Y1 - 2002 ER - TY - JOUR A1 - Schmitz-Hertzberg, Sebastian-Tim A1 - Liese, Rick A1 - Terjung, Carsten A1 - Bier, Frank Fabian T1 - Towards a smart encapsulation system for small-sized electronic devices: a new approach JF - International journal of polymer science N2 - Miniaturized analytical chip devices like biosensors nowadays provide assistance in highly diverse fields of application such as point-of-care diagnostics and industrial bioprocess engineering. However, upon contact with fluids, the sensor requires a protective shell for its electrical components that simultaneously offers controlled access for the target analytes to the measuring units. We therefore developed a capsule that comprises a permeable and a sealed compartment consisting of variable polymers such as biocompatible and biodegradable polylactic acid (PLA) for medical applications or more economical polyvinyl chloride (PVC) and polystyrene (PS) polymers for bioengineering applications. Production of the sealed capsule compartments was performed by heat pressing of polymer pellets placed in individually designable molds. Controlled permeability of the opposite compartments was achieved by inclusion of NaCl inside the polymer matrix during heat pressing, followed by its subsequent release in aqueous solution. Correlating diffusion rates through the so made permeable capsule compartments were quantified for preselected model analytes: glucose, peroxidase, and polystyrene beads of three different diameters (1.4 mu m, 4.2 mu m, and 20.0 mu m). In summary, the presented capsule system turned out to provide sufficient shelter for small-sized electronic devices and gives insight into its potential permeability for defined substances of analytical interest. Y1 - 2014 U6 - https://doi.org/10.1155/2014/713603 SN - 1687-9422 SN - 1687-9430 PB - Hindawi Publishing Corp. CY - New York ER - TY - JOUR A1 - Sachse, Rita A1 - Wüstenhagen, Doreen Anja A1 - Samalikova, Maria A1 - Gerrits, Michael A1 - Bier, Frank Fabian A1 - Kubick, Stefan T1 - Synthesis of membrane proteins in eukaryotic cell-free systems JF - Engineering in life sciences : Industry, Environment, Plant, Food N2 - Cell-free protein synthesis (CFPS) is a valuable method for the fast expression of difficult-to-express proteins as well as posttranslationally modified proteins. Since cell-free systems circumvent possible cytotoxic effects caused by protein overexpression in living cells, they significantly enlarge the scale and variety of proteins that can be characterized. We demonstrate the high potential of eukaryotic CFPS to express various types of membrane proteins covering a broad range of structurally and functionally diverse proteins. Our eukaryotic cell-free translation systems are capable to provide high molecular weight membrane proteins, fluorescent-labeled membrane proteins, as well as posttranslationally modified proteins for further downstream analysis. KW - Cell-free protein expression KW - In vitro protein synthesis KW - Labeled membrane proteins KW - Synthetic glycoprotein Y1 - 2013 U6 - https://doi.org/10.1002/elsc.201100235 SN - 1618-0240 VL - 13 IS - 1 SP - 39 EP - 48 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Reiss, Edda A1 - Hoelzel, Ralph A1 - Bier, Frank Fabian T1 - Synthesis and stretching of rolling circle amplification products in a flow-through system N2 - Enzymatic isothermal rolling circle amplification (RCA) produces long concatemeric single-stranded DNA (ssDNA) molecules if a small circular ssDNA molecule is applied as the template. A method is presented here in which the RCA reaction is carried out in a flow-through system, starting from isolated surface-tethered DNA primers. This approach combines gentle fluidic handling of the single-stranded RCA products, such as staining or stretching via a receding meniscus, with the option of simultaneous (fluorescence) microscopic observation. It is shown that the stretched and surface-attached RCA products are accessible for hybridization of complementary oligonucleotides, which demonstrates their addressability by complementary base pairing. The long RCA products should be well suited to bridge the gap between biomolecular nanoscale building-blocks and structures at the micro- and macroscale, especially at the single- molecule level presented here. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/107640323 U6 - https://doi.org/10.1002/smll.200900319 SN - 1613-6810 ER - TY - JOUR A1 - Grießner, Matthias A1 - Hartig, Dave A1 - Christmann, Alexander A1 - Ehrentreich-Förster, Eva A1 - Warsinke, Axel A1 - Bier, Frank Fabian T1 - Surface regeneration of microfluidic microarray printheads through plasma techniques N2 - This work describes a method for surface regeneration of microfluidic microarray printheads through plasma techniques. Modification procedures were chosen in a way to obtain high reproducibility with a minimum of time consumption. The idea behind this is a complete regeneration of a microarray printhead before or after usage to achieve best printing results over a typical print job. A sequence of low-pressure oxygen-plasma and plasma polymerization with hexamethyldisiloxane (HMDSO) was used to regenerate printheads. Proof of the concept is given through quality control performed with a spotter implemented CCD camera, contact angle measurements and a typical hybridization experiment. Stable printing results were obtained over 3000 activations showing that the presented method is suitable for treatment of microarray printheads. Y1 - 2010 UR - http://iopscience.iop.org/0960-1317/ U6 - https://doi.org/10.1088/0960-1317/20/3/037002 SN - 0960-1317 ER - TY - JOUR A1 - Hüttl, Christine A1 - Hettrich, Cornelia A1 - Miller, Reinhard A1 - Paulke, Bernd-Reiner A1 - Henklein, Petra A1 - Rawel, Harshadrai Manilal A1 - Bier, Frank Fabian T1 - Self-assembled peptide amphiphiles function as multivalent binder with increased hemagglutinin affinity JF - BMC biotechnology N2 - Background: A promising way in diagnostic and therapeutic applications is the development of peptide amphiphiles (PAs). Peptides with a palmitic acid alkylchain were designed and characterized to study the effect of the structure modifications on self-assembling capabilities and the multiple binding capacity to hemagglutinin (HA), the surface protein of influenza virus type A. The peptide amphiphiles consists of a hydrophilic headgroup with a biological functionality of the peptide sequence and a chemically conjugated hydrophobic tail. In solution they self-assemble easily to micelles with a hydrophobic core surrounded by a closely packed peptide-shell. Results: In this study the effect of a multiple peptide binding partner to the receptor binding site of HA could be determined with surface plasmon resonance measurements. The applied modification of the peptides causes signal amplification in relationship to the unmodified peptide wherein the high constant specificity persists. The molecular assembly of the peptides was characterized by the determination of critical micelle concentration (CMC) with concentration of 10(-5) M and the colloidal size distribution. Conclusion: The modification of the physico-chemical parameters by producing peptide amphiphiles form monomeric structures which enhances the binding affinity and allows a better examination of the interaction with the virus surface protein hemagglutinin. KW - CMC KW - Influenza virus detection KW - Micelle KW - PAs KW - Surface plasmon resonance Y1 - 2013 U6 - https://doi.org/10.1186/1472-6750-13-51 SN - 1472-6750 VL - 13 IS - 22 PB - BioMed Central CY - London ER -