@article{SchenkFettkeLenzetal.2012, author = {Schenk, J{\"o}rg A. and Fettke, J{\"o}rg and Lenz, Christine and Albers, Katharina and Mallwitz, Frank and Gajovic-Eichelmann, Nenad and Ehrentreich-F{\"o}rster, Eva and Kusch, Emely and Sellrie, Frank}, title = {Secretory leukocyte protease inhibitor (SLPI) might contaminate murine monoclonal antibodies after purification on protein G}, series = {Journal of biotechnology}, volume = {158}, journal = {Journal of biotechnology}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2011.12.025}, pages = {34 -- 35}, year = {2012}, abstract = {The large scale production of a monoclonal anti-progesterone antibody in serum free medium followed by affinity chromatography on protein G lead to a contamination of the antibody sample with a protein of about 14 kDa. This protein was identified by mass spectrometry as secretory leukocyte protease inhibitor (SLPI). This SLPI contamination lead to a failure of the fiber-optic based competitive fluorescence assay to detect progesterone in milk. Purification of the monoclonal antibody using protein A columns circumvented this problem.}, language = {en} } @article{SchellerMakowerGhindilisetal.1995, author = {Scheller, Frieder W. and Makower, Alexander and Ghindilis, A. L. and Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and Wollenberger, Ursula and Bauer, Christian G. and Micheel, Burkhard and Pfeiffer, Dorothea and Szeponik, Jan and Michael, N. and Kaden, H.}, title = {Enzyme sensors for subnanomolar concentrations}, year = {1995}, language = {en} } @article{SchellerJinEhrentreichFoersteretal.1999, author = {Scheller, Frieder W. and Jin, Wen and Ehrentreich-F{\"o}rster, Eva and Ge, Bixia and Lisdat, Fred and B{\"u}ttemeyer, R. and Wollenberger, Ursula}, title = {Cytochrome c based superoxide sensor for in vivo application}, year = {1999}, language = {en} } @misc{MemczakLausterKaretal.2016, author = {Memczak, Henry and Lauster, Daniel and Kar, Parimal and Di Lella, Santiago and Volkmer, Rudolf and Knecht, Volker and Herrmann, Andreas and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian and St{\"o}cklein, Walter F. M.}, title = {Anti-hemagglutinin antibody derived lead peptides for inhibitors of influenza virus binding}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {536}, issn = {1866-8372}, doi = {10.25932/publishup-41087}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410872}, pages = {24}, year = {2016}, abstract = {Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/MuteSwan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing.}, language = {en} } @article{LisdatGeEhrentreichFoersteretal.1999, author = {Lisdat, Fred and Ge, Bixia and Ehrentreich-F{\"o}rster, Eva and Reszka, R. and Scheller, Frieder W.}, title = {SOD activity measurement using cytochrome c modified electrode}, year = {1999}, language = {en} } @article{KleinjungEhrentreichFoersterScheller1999, author = {Kleinjung, Frank and Ehrentreich-F{\"o}rster, Eva and Scheller, Frieder W.}, title = {Changing functionality of surfaces by directed self-assembly using oligonucleotides - the oligo-tag}, year = {1999}, language = {en} } @article{GriessnerHartigChristmannetal.2010, author = {Grießner, Matthias and Hartig, Dave and Christmann, Alexander and Ehrentreich-F{\"o}rster, Eva and Warsinke, Axel and Bier, Frank Fabian}, title = {Surface regeneration of microfluidic microarray printheads through plasma techniques}, issn = {0960-1317}, doi = {10.1088/0960-1317/20/3/037002}, year = {2010}, abstract = {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.}, language = {en} } @article{GriessnerBroekerLehmannetal.2009, author = {Grießner, Matthias and Broeker, Patrick and Lehmann, Andr{\´e} and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian}, title = {Detection of angiotensin II type 1 receptor ligands by a cell-based assay}, issn = {1618-2642}, doi = {10.1007/s00216-009-3074-4}, year = {2009}, abstract = {This work describes a cell-based assay that does not depend on radioactivity or laboratory animals for the detection of ligands of angiotensin II type 1 receptor (AT(1)R). The assay makes use of stable transfected Chinese hamster ovary cells (CHO-AT(1)R) expressing the AT(1)R. A sequential saturation assay principle was used in which receptor binding sites of the CHO-AT(1)R cells are blocked by the analyte in a concentration-dependent manner. Afterwards, TAMRA-angiotensin II, a fluorescence-labeled ligand, was added to bind to the remaining free binding sites of the receptor. In consequence, the fluorescence signal determined is inversely proportional to the concentration of the analyte.}, language = {en} } @article{GriessnerHartigChristmannetal.2011, author = {Griessner, Matthias and Hartig, Dave and Christmann, Alexander and Pohl, Carsten and Schellhase, Michaela and Ehrentreich-F{\"o}rster, Eva}, title = {Development and characterization of a disposable plastic microarray printhead}, series = {Biomedical microdevices : bioMEMS and biomedical nanotechnology}, volume = {13}, journal = {Biomedical microdevices : bioMEMS and biomedical nanotechnology}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {1387-2176}, doi = {10.1007/s10544-011-9522-x}, pages = {533 -- 538}, year = {2011}, abstract = {During the last decade microarrays have become a powerful analytical tool. Commonly microarrays are produced in a non-contact manner using silicone printheads. However, silicone printheads are expensive and not able to be used as a disposable. Here, we show the development and functional characterization of 8-channel plastic microarray printheads that overcome both disadvantages of their conventional silicone counterparts. A combination of injection-molding and laser processing allows us to produce a high quantity of cheap, customizable and disposable microarray printheads. The use of plastics (e.g., polystyrene) minimizes the need for surface modifications required previously for proper printing results. Time-consuming regeneration processes, cleaning procedures and contaminations caused by residual samples are avoided. The utilization of plastic printheads for viscous liquids, such as cell suspensions or whole blood, is possible. Furthermore, functional parts within the plastic printhead (e.g., particle filters) can be included. Our printhead is compatible with commercially available TopSpot devices but provides additional economic and technical benefits as compared to conventional TopSpot printheads, while fulfilling all requirements demanded on the latter. All in all, this work describes how the field of traditional microarray spotting can be extended significantly by low cost plastic printheads.}, language = {en} } @article{EttlingerSchenkMicheeletal.2012, author = {Ettlinger, Julia and Schenk, J{\"o}rg A. and Micheel, Burkhard and Ehrentreich-F{\"o}rster, Eva and Gajovic-Eichelmann, Nenad}, title = {A direct competitive homogeneous immunoassay for progesterone - the Redox Quenching Immunoassay}, series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, volume = {24}, journal = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis}, number = {7}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1040-0397}, doi = {10.1002/elan.201200107}, pages = {1567 -- 1575}, year = {2012}, abstract = {A direct competitive amperometric immunoassay format for the detection of haptens and proteins was developed. The method is based on the quenching of electroactivity of ferrocenium, which is coupled to the antigen and used as the primary reporter, upon binding to a monoclonal anti-ferrocenium antibody, which is coupled to the detection antibody and used as a secondary reporter. A separation-free progesterone immunoassay with a lower detection limit of 1 ng?mL-1 (3.18 nmol?L-1) in 1?:?2 diluted blood serum was realised by combining two bifunctional conjugates, a ferrocenium-PEG-progesterone tracer and a bioconjugate of one anti-progesterone and one anti-ferrocenium antibody. The immune complex is formed within 30 s upon addition of progesterone, resulting in a total analysis time of 1.5 min.}, language = {en} } @article{EhrentreichFoersterShishniashviliSongetal.1998, author = {Ehrentreich-F{\"o}rster, Eva and Shishniashvili, D. and Song, Min Ik and Scheller, Frieder W.}, title = {Study of antioxidative substances by means of a ssuperoxide sensor}, year = {1998}, language = {en} } @article{EhrentreichFoersterSchellerBier2003, author = {Ehrentreich-F{\"o}rster, Eva and Scheller, Frieder W. and Bier, Frank Fabian}, title = {Detection of progesterone in whole blood samples}, year = {2003}, abstract = {The progesterone concentration in blood samples can be utilised as a marker for the diagnosis of early pregnancy, endocrinopathy and virilism. Here, we describe a method for progesterone detection and measurement in whole blood samples by a surface sensitive biosensor used in conjunction with an integrated optical grating coupler. This device determines refractive index changes near the biosensor's surface. Hence, biological species bound to a surface layer can be measured in real-time without any label. For the measurements, we have modified the indirect competitive immonoassay principle. The concentration of the progesterone antibody was kept at 1 µg/ml. Progesterone concentration was determined in buffer solution and whole blood in a range between 0.005 and 10 ng/ml. The detection limit was determined to be 3 pM. The relative standard deviation was calculated to be 3.5\%.}, language = {en} } @article{BierEhrentreichFoersterSchelleretal.1996, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and Scheller, Frieder W. and Makower, Alexander and Eremenko, A. V. and Wollenberger, Ursula and Bauer, Christian G. and Pfeiffer, Dorothea and Micheel, Burkhard}, title = {Ultrasensitive biosensors}, year = {1996}, language = {en} } @article{BierEhrentreichFoersterScheller1996, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and Scheller, Frieder W.}, title = {Amplifying bienzyme cycle-linked immunoassays for determination of 2,4- dichlorphenoxyacetic acid}, year = {1996}, language = {en} } @article{BierEhrentreichFoersterMakoweretal.1996, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and Makower, Alexander and Scheller, Frieder W.}, title = {An enzymatic amplification cycle for high sensitive immunoassay}, year = {1996}, language = {en} } @article{BierEhrentreichFoersterDoellingetal.1997, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and D{\"o}lling, R. and Eremenko, A. V. and Scheller, Frieder W.}, title = {A redox-label immunosensor on basis of a bi-enzyme electrode}, year = {1997}, language = {en} } @article{BierEhrentreichFoersterBaueretal.1996, author = {Bier, Frank Fabian and Ehrentreich-F{\"o}rster, Eva and Bauer, Christian G. and Scheller, Frieder W.}, title = {High sensitive competitive immunodetection of 2,4-dichlorophenoxyacetic acid using enzymatic amplification with electrochemical detection}, year = {1996}, language = {en} } @article{BauerEremenkoEhrentreichFoersteretal.1996, author = {Bauer, Christian G. and Eremenko, A. V. and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian and Makower, Alexander and Halsall, H. B. and Heineman, W. R. and Scheller, Frieder W.}, title = {Zeptomole-detecting biosensor for alkaline phosphatase in an electroche mical immunoassay for 2,4- dichlorophenoacetic acid}, year = {1996}, language = {en} } @article{AndresenGroetzingerZarseetal.2006, author = {Andresen, Heiko and Gr{\"o}tzinger, Carsten and Zarse, Kim and Birringer, Marc and Hessenius, Carsten and Kreuzer, Oliver Johannes and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian}, title = {Peptide microarrays with site-specifically immobilized synthetic peptides for antibody diagnostics}, issn = {0925-4005}, doi = {10.1016/j.snb.2005.07.033}, year = {2006}, abstract = {Peptide microarrays bear the potential to discover molecular recognition events on protein level, particularly in the field of molecular immunology, in a manner and with an efficiency comparable to the performance of DNA microarrays. We developed a novel peptide microarray platform for the detection of antibodies in liquid samples. The system comprises site-specific solution phase coupling of biotinylated peptides to NeutrAvidin, localized microdispensing of peptide-NeutrAvidin conjugates onto activated glass slides and a fluorescence immuno sandwich assay format for antibody capture and detection. Our work includes synthetic peptides deduced from amino acid sequences of immunodominant linear epitopes, such as the T7 phage capsid protein, Herpes simplex virus glycoprotein D, c-myc protein and three domains of the Human coronavirus 229E polymerase polyprotein. We demonstrate that our method produces peptide arrays with excellent spot morphology which are capable of specific and sensitive detection of monoclonal antibodies from fluid samples.}, language = {en} } @article{AndresenGrotzingerZarseetal.2006, author = {Andresen, Heiko and Grotzinger, Carsten and Zarse, Kim and Kreuzer, Oliver Johannes and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian}, title = {Functional peptide microarrays for specific and sensitive antibody diagnostics}, issn = {1615-9853}, doi = {10.1002/pmic.200500343}, year = {2006}, abstract = {Peptide microarrays displaying biologically active small synthetic peptides in a high-density format provide an attractive technology to probe complex samples for the presence and/or function of protein analytes. We present a new approach for manufacturing functional peptide microarrays for molecular immune diagnostics. Our method relies on the efficiency of site-specific solution-phase coupling of biotinylated synthetic peptides to NeutrAvidin (NA) and localized microdispensing of peptide-NA-complexes onto activated glass surfaces. Antibodies are captured in a sandwich manner between surface immobilized peptide probes and fluorescence-labeled secondary antibodies. Our work includes a total of 54 peptides derived from immunodominant linear epitopes of the T7 phage capsid protein, Herpes simplex virus glycoprotein D, c-myc protein, and three domains of the Human coronavirus polymerase polyprotein and their cognate mAbs. By using spacer molecules of different type and length for NA-mediated peptide presentation, we show that the incorporation of a minimum spacer length is imperative for antibody binding, whereas the peptide immobilization direction has only secondary importance for antibody affinity and binding. We further demonstrate that the peptide array is capable of detecting low-picomolar concentrations of mAbs in buffered solutions and diluted human serum with high specificity}, language = {en} }