Petra S. Dittrich

Last Name

Dittrich

First Name

Petra S.

ORCID

0000-0001-5359-8403

Organisational unit

03807 - Dittrich, Petra / Dittrich, Petra

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Publications 1 - 10 of 231

Multimodal analysis of phytase-producing yeast in nanoliter droplet arrays
Hümmer, Dominik; Bachler, Simon; Köhler, Michael; et al. (2018)
22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2018)
We present an automated platform to perform enzymatic assays in nanoliter droplet arrays with multimodal readout. We analyzed the animal feed additive phytase, an industrially-relevant enzyme, which was expressed and secreted by recombinant yeast cells encapsulated in droplets. The relative enzyme concentration could be determined by time-lapse fluorescence spectroscopy. Moreover, the progress of the multistep phytase-catalyzed reaction of non-fluorogenic substrates was directly monitored by mass spectrometry (MS), without the need of further purification.
Tunable Membrane Potential Reconstituted in Giant Vesicles Promotes Permeation of Cationic Peptides at Nanomolar Concentrations
Lin, Chao-Chen; Bachmann, Michael; Bachler, Simon; et al. (2018)
ACS Applied Materials & Interfaces
Challenges and opportunities of wearable molecular sensors in endocrinology and metabolism
Güntner, Andreas T.; Gerber, Philipp A.; Dittrich, Petra S.; et al. (2026)
Nature Reviews Endocrinology
Wearable technologies that analyse non-conventional biological matrices, such as interstitial fluid, sweat, tears or breath, have the potential to provide longitudinal biomarker data with minimal invasiveness. These data could provide insights into physiological and behavioural patterns, in particular outside medical care facilities. Despite the success of continuous glucose monitoring, the adoption of wearable sensors for managing endocrine and metabolic diseases remains limited. This Perspective highlights five key challenges and proposes solutions. First, understanding the physiology of longitudinal biomarker profiles is crucial for uncovering rhythmic patterns and physiological interrelations in the prediction of health trajectories. Second, technical barriers currently hinder the continuous monitoring of most clinically relevant biomarkers. Third, machine learning models often struggle with the complexity of dense biomarker datasets, which increases the risk of spurious correlations. Fourth, the diagnostic value of wearable sensor data requires validation through clinical studies, and predicting treatment outcomes necessitates diverse and large patient cohorts over extended observation periods in real-world settings. Finally, most wearable devices function as isolated solutions. Thus, they lack interoperability and integration into clinical pathways, and often fail to incorporate context and user input. Addressing these challenges will be key for advancing the role of wearable sensors in endocrine and metabolic care in future health-care settings.
Single cell analysis in a multilayer microfluidic device: Monitoring of drug-induced gene expression
Hanke, Conni; Waide, Sara; Kettler, Raffael; et al. (2011)
15th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2011)
Current trends in single cell analysis
Dittrich, Petra S.; Jakubowski, Norbert (2014)
Analytical and Bioanalytical Chemistry
Generating cell co-cultures by rapid cell adhesion on opposite sides of polyester membranes
Hanke, Conni; Dittrich, Petra S.; Reyes, D. R. (2012)
Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2012)
Two-Layer Droplet Arrays Enable Dynamic Manipulation of Cell Microenvironment During High-Throughput Bacterial Cultivation
Xiong, Bijing; Breitfeld, Maximilian; Dittrich, Petra S. (2025)
Small Methods
Arrays of pico-to-microliter droplets, organized on a surface, enable chemical and biological workflows at high throughput. Here, a platform employing two-layer droplets is presented to enable flexible manipulation of the droplets’ microenvironment for dynamic biological cultivation. Arrays of 6784 agarose droplets (≈2.0 nL per droplet) encapsulating and immobilizing bacterial cells are generated. After that, aqueous droplets (≈3.7 nL) with a defined composition are deposited atop to form a thin liquid layer surrounding the agarose droplets. Chemical exchange between the two layers is extremely fast (equilibrium within 15 s for fluorescein). Moreover, the aqueous layer can be removed, opening the possibility to extract substances from the agarose droplets. Indeed, repeated addition and aspiration of a buffer successfully remove dyes or drugs previously added to the agarose droplets. Therefore, antibiotic drug testing can be performed under both static and transient exposure profiles. The latter reveals that bacterial responses such as bacterial killing and resuscitation are both heterogeneous at the single-cell level. Last, it is exemplified how such droplet manipulation strategy can also be use in long-term experimentation, where medium replenishment, performed at 12-h intervals during a 72-h experiment, enables the cultivation of a slow-growing microorganism in nanoliter droplets.
Observations of Membrane Domain Reorganization in Mechanically Compressed Artificial Cells
Robinson, Tom; Dittrich, Petra S. (2019)
ChemBioChem
The iron chelator Deferasirox causes severe mitochondrial swelling without depolarization due to a specific effect on inner membrane permeability
Gottwald, Esther M.; Schuh, Claus D.; Drücker, Patrick; et al. (2020)
Scientific Reports
The iron chelator Deferasirox (DFX) causes severe toxicity in patients for reasons that were previously unexplained. Here, using the kidney as a clinically relevant in vivo model for toxicity together with a broad range of experimental techniques, including live cell imaging and in vitro biophysical models, we show that DFX causes partial uncoupling and dramatic swelling of mitochondria, but without depolarization or opening of the mitochondrial permeability transition pore. This effect is explained by an increase in inner mitochondrial membrane (IMM) permeability to protons, but not small molecules. The movement of water into mitochondria is prevented by altering intracellular osmotic gradients. Other clinically used iron chelators do not produce mitochondrial swelling. Thus, DFX causes organ toxicity due to an off-target effect on the IMM, which has major adverse consequences for mitochondrial volume regulation.
A new microfluidics-based droplet dispenser for ICPMS
Verboket, Pascal E.; Borovinskaya, Olga; Meyer, Nicole; et al. (2014)
Analytical Chemistry
In this work, a novel droplet microfluidic sample introduction system for inductively coupled plasma mass spectrometry (ICPMS) is proposed and characterized. The cheap and disposable microfluidic chip generates droplets of an aqueous sample in a stream of perfluorohexane (PFH), which is also used to eject them as a liquid jet. The aqueous droplets remain intact during the ejection and can be transported into the ICP with >50% efficiency. The transport is realized via a custom-built system, which includes a membrane desolvator necessary for the PFH vapor removal. The introduction system presented here can generate highly monodisperse droplets in the size range of 40–60 μm at frequencies from 90 to 300 Hz. These droplets produced very stable signals with a relative standard deviation (RSD) comparable to the one achieved with a commercial droplet dispenser. Using the current system, samples with a total volume of <1 μL can be analyzed. Moreover, the capabilities of the setup for introduction and quantitative elemental analysis of single cells were described using a test system of bovine red blood cells. In the future, other modules of the modern microfludics can be integrated in the chip, such as on-chip sample pretreatment or parallel introduction of different samples.

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Petra S. Dittrich

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