TY - JOUR A1 - Kagel, Heike A1 - Bier, Frank Fabian A1 - Frohme, Marcus A1 - Glökler, Jörn T1 - A Novel Optical Method To Reversibly Control Enzymatic Activity Based On Photoacids JF - Scientific Reports N2 - Most biochemical reactions depend on the pH value of the aqueous environment and some are strongly favoured to occur in an acidic environment. A non-invasive control of pH to tightly regulate such reactions with defined start and end points is a highly desirable feature in certain applications, but has proven difficult to achieve so far. We report a novel optical approach to reversibly control a typical biochemical reaction by changing the pH and using acid phosphatase as a model enzyme. The reversible photoacid G-acid functions as a proton donor, changing the pH rapidly and reversibly by using high power UV LEDs as an illumination source in our experimental setup. The reaction can be tightly controlled by simply switching the light on and off and should be applicable to a wide range of other enzymatic reactions, thus enabling miniaturization and parallelization through non-invasive optical means. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12685 SN - 2045-2322 VL - 9 ER - TY - JOUR A1 - Kagel, Heike A1 - Jacobs, Hannes A1 - Bier, Frank Fabian A1 - Glökler, Jörn A1 - Frohme, Marcus T1 - A Novel Microtiter Plate Format High Power Open Source LED Array JF - Photonics N2 - Many photochemical or photobiological applications require the use of high power ultraviolet light sources, such as high-pressure mercury arc lamps. In addition, many photo-induced chemical, biochemical and biological applications require either a combinatorial setting or a parallel assay of multiple samples under the same environmental conditions to ensure reproducibility. To achieve this, alternative, controllable light sources, such as ultraviolet light emitting diodes (UV LEDs) with high power and spatial control are required. Preferably, LEDs are arranged in a suitable standardized 96-well microtiter plate format. We designed such an array and established the methods required for heat management and enabling stable, controllable illumination over time. KW - optics KW - photonics KW - light KW - LED array KW - High-power LED KW - 365 nm KW - microtiter plate Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-11307 SN - 2304-6732 VL - 6 IS - 1 ER - TY - JOUR A1 - Fischbach, Jens A1 - Loh, Qiuting A1 - Bier, Frank Fabian A1 - Lim, Theam Soon A1 - Frohme, Marcus A1 - Glökler, Jörn T1 - Alizarin Red S for Online Pyrophosphate Detection Identified by a Rapid Screening Method JF - Scientific Reports N2 - We identified Alizarin Red S and other well known fluorescent dyes useful for the online detection of pyrophosphate in enzymatic assays, including the loop mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR) assays. An iterative screening was used for a selected set of compounds to first secure enzyme compatibility, evaluate inorganic pyrophosphate sensitivity in the presence of manganese as quencher and optimize conditions for an online detection. Of the selected dyes, the inexpensive alizarin red S was found to selectively detect pyrophosphate under LAMP and PCR conditions and is superior with respect to its defined red-shifted spectrum, long shelf life and low toxicity. In addition, the newly identified properties may also be useful in other enzymatic assays which do not generate nucleic acids but are based on inorganic pyrophosphate. Finally, we propose that our screening method may provide a blueprint for rapid screening of compounds for detecting inorganic pyrophosphate. KW - biochemical assay KW - fluorescent dye KW - screening Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9248 SN - 2045-2322 VL - 7 ER -