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 - Folman, R. A1 - Krüger, P. A1 - Schmiedmayer, Jörg A1 - Denschlag, J. H. A1 - Henkel, Carsten T1 - Microscopic atom optics : from wires to an atom chip N2 - We review the 10 year long journey into the miniaturization and integration of matter wave optics resulting in devices mounted on surfaces, so called atom chips. The first experiments started with the guiding of atoms with free standing wires and investigated the trapping potentials in simple geometries. Atom optical elements can now be micro fabricated down to 1 um size on atom chips. The creation of a Bose-Einstein condensate miniaturized in surface traps was recently achieved, and the first attempts to integrate light optics are in progress. In this review, we describe microscopic atom optics elements using current carrying and charged structures. Experiments with free standing structures (atom wires)are reviewed, investigating the basic principles of microscopic atom optics. We then discuss the miniaturization on the atom chip. One of the open central questions is dealt with: what happens with cold atoms close to a warm surface, how fast will they heat up or lose their coherence? The review concludes with an outlook of what we believe the future directions to be, and what can be hoped for. Y1 - 2002 ER - TY - JOUR A1 - Zhang, B. A1 - Henkel, Carsten A1 - Haller, E. A1 - Wildermuth, S. A1 - Hofferberth, S. A1 - Kruger, P. A1 - Schmiedmayer, Jörg T1 - Relevance of sub-surface chip layers for the lifetime of magnetically trapped atoms N2 - We investigate the lifetime of magnetically trapped atoms above a planar, layered atom chip structure. Numerical calculations of the thermal magnetic noise spectrum are performed, based on the exact magnetic Green function and multi layer reflection coefficients. We have performed lifetime measurements where the center of a side guide trap is laterally shifted with respect to the current carrying wire using additional bias fields. Comparing the experiment to theory, we find a fair agreement and demonstrate that for a chip whose topmost layer is metallic, the magnetic noise depends essentially on the thickness of that layer, as long as the layers below have a, much smaller conductivity; essentially the same magnetic noise would be obtained with a metallic membrane suspended in vacuum. Based on our theory we give general scaling laws of how to reduce the effect of surface magnetic noise on the trapped atoms Y1 - 2005 ER - TY - JOUR A1 - Henkel, Carsten A1 - Krüger, P. A1 - Folman, R. A1 - Schmiedmayer, Jörg T1 - Fundamental limits for coherent manipulation on atom chips Y1 - 2003 SN - 0946-2171 ER - TY - JOUR A1 - Agarwal, Saloni A1 - Warmt, Christian A1 - Henkel, Jörg A1 - Schrick, Livia A1 - Nitsche, Andreas A1 - Bier, Frank Fabian T1 - Lateral flow-based nucleic acid detection of SARS-CoV-2 using enzymatic incorporation of biotin-labeled dUTP for POCT use JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica N2 - The degree of detrimental effects inflicted on mankind by the COVID-19 pandemic increased the need to develop ASSURED (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, and Deliverable) POCT (point of care testing) to overcome the current and any future pandemics. Much effort in research and development is currently advancing the progress to overcome the diagnostic pressure built up by emerging new pathogens. LAMP (loop-mediated isothermal amplification) is a well-researched isothermal technique for specific nucleic acid amplification which can be combined with a highly sensitive immunochromatographic readout via lateral flow assays (LFA). Here we discuss LAMP-LFA robustness, sensitivity, and specificity for SARS-CoV-2 N-gene detection in cDNA and clinical swab-extracted RNA samples. The LFA readout is designed to produce highly specific results by incorporation of biotin and FITC labels to 11-dUTP and LF (loop forming forward) primer, respectively. The LAMP-LFA assay was established using cDNA for N-gene with an accuracy of 95.65%. To validate the study, 82 SARS-CoV-2-positive RNA samples were tested. Reverse transcriptase (RT)-LAMP-LFA was positive for the RNA samples with an accuracy of 81.66%; SARS-CoV-2 viral RNA was detected by RT-LAMP-LFA for as low as CT-33. Our method reduced the detection time to 15 min and indicates therefore that RT-LAMP in combination with LFA represents a promising nucleic acid biosensing POCT platform that combines with smartphone based semi-quantitative data analysis. KW - Point of care testing (POCT) KW - Lateral flow assay (LFA) KW - COVID-19 KW - Reverse transcription loop-mediated isothermal amplification (RT-LAMP); KW - SARS-CoV-2 N-gene Y1 - 2022 U6 - https://doi.org/10.1007/s00216-022-03880-4 SN - 1618-2642 SN - 1618-2650 VL - 414 IS - 10 SP - 3177 EP - 3186 PB - Springer CY - Heidelberg ER -