Lab on a Chip

Journal: Lab on a Chip

Abbreviation

Lab chip

Publisher

Royal Society of Chemistry

ISSN

1473-0197
1473-0189

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Publications 1 - 10 of 166

A hybrid dielectrophoretic trap-optical tweezers platform for manipulating microparticles in aqueous suspension
González-Gómez, Carlos David; García Guirado, Jose; Quidant, Romain; et al. (2025)
Lab on a Chip
We demonstrate that a set of microfabricated electrodes can be coupled to a commercial optical tweezers device, implementing a hybrid electro-optical platform with multiple functionalities for the manipulation of micro-/nanoparticles in suspension. We show that the hybrid scheme allows enhanced manipulation capabilities, including hybrid dynamics, controlled accumulation in the dielectrophoretic trap from the optical tweezers, selectivity, and video tracking of the individual trajectories of trapped particles. This creates opportunities for novel studies in statistical physics and stochastic thermodynamics with multi-particle systems, previously limited to investigations with individual particles.
Investigating the fluid dynamics of rapid processes within microfluidic devices using bright-field microscopy
Pirbodaghi, Tohid; Vigolo, Daniele; Akbari, Samin; et al. (2015)
Lab on a Chip
Real-time tracking, retrieval and gene expression analysis of migrating human T cells
Mehling, Matthias; Frank, Tino; Albayrak, Cem; et al. (2015)
Lab on a Chip
Antibodies, repertoires and microdevices in antibody discovery and characterization
Schlotheuber, Luca Johannes; Lüchtefeld, Ines; Eyer, Klaus (2024)
Lab on a Chip
Therapeutic antibodies are paramount in treating a wide range of diseases, particularly in auto-immunity, inflammation and cancer, and novel antibody candidates recognizing a vast array of novel antigens are needed to expand the usefulness and applications of these powerful molecules. Microdevices play an essential role in this challenging endeavor at various stages since many general requirements of the overall process overlap nicely with the general advantages of microfluidics. Therefore, microfluidic devices are rapidly taking over various steps in the process of new candidate isolation, such as antibody characterization and discovery workflows. Such technologies can allow for vast improvements in timelines and incorporate conservative antibody stability and characterization assays, but most prominently screenings and functional characterization within integrated workflows due to high throughput and standardized workflows. First, we aim to provide an overview of the challenges of developing new therapeutic candidates, their repertoires and requirements. Afterward, this review focuses on the discovery of antibodies using microfluidic systems, technological aspects of micro devices and small-scale antibody protein characterization and selection, as well as their integration and implementation into antibody discovery workflows. We close with future developments in microfluidic detection and antibody isolation principles and the field in general.
An automated microfluidic system for efficient capture of rare cells and rapid flow-free stimulation
Dettinger, Philip; Wang, Weijia; Ahmed, Nouraiz; et al. (2020)
Lab on a Chip
Cell fates are controlled by environmental stimuli that rapidly change the activity of intracellular signaling. Studying these processes requires rapid manipulations of micro-environmental conditions while continuously observing single cells over long periods of time. Current microfluidic devices are unable to simultaneously i) efficiently capture and concentrate rare cells, ii) conduct automated rapid media exchanges via diffusion without displacing non-adherent cells, and iii) allow sensitive high-throughput long-term time-lapse microscopy. Hematopoietic stem and progenitor cells pose a particular challenge for these types of experiments as they are impossible to obtain in very large numbers and are displaced by the fluid flow usually used to change culture media, thus preventing cell tracking. Here, we developed a programmable automated system composed of a novel microfluidic device for efficient capture of rare cells in independently addressable culture chambers, a custom incubation system, and user-friendly control software. The chip's culture chambers are optimized for efficient and sensitive fluorescence microscopy and their media can be individually and quickly changed by diffusion without non-adherent cell displacement. The chip allows efficient capture, stimulation, and sensitive high-frequency time-lapse observation of rare and sensitive murine and human primary hematopoietic stem cells. Our 3D-printed humidification and incubation system minimizes gas consumption, facilitates chip setup, and maintains stable humidity and gas composition during long-term cell culture. This approach now enables the required continuous long-term single-cell quantification of rare non-adherent cells with rapid environmental manipulations, e.g. of rapid signaling dynamics and the later stem cell fate choices they control.
Acoustofluidic medium exchange for preparation of electrocompetent bacteria using channel wall trapping
Gerlt, Michael; Ruppen, Peter; Leuthner, Moritz; et al. (2021)
Lab on a Chip
Comprehensive integration of process steps into a miniaturised version of synthetic biology workflows remains a crucial task in automating the design of biosystems. However, each of these process steps has specific demands with respect to the environmental conditions, including in particular the composition of the surrounding fluid, which makes integration cumbersome. As a case in point, transformation, i.e. reprogramming of bacteria by delivering exogenous genetic material (such as DNA) into the cytoplasm, is a key process in molecular engineering and modern biotechnology in general. Transformation is often performed by electroporation, i.e. creating pores in the membrane using electric shocks in a low conductivity environment. However, cell preparation for electroporation can be cumbersome as it requires the exchange of growth medium (high-conductivity) for low-conductivity medium, typically performed via multiple time-intensive centrifugation steps. To simplify and miniaturise this step, we developed an acoustofluidic device capable of trapping the bacterium Escherichia coli non-invasively for subsequent exchange of medium, which is challenging in acoustofluidic devices due to detrimental acoustic streaming effects. With an improved etching process, we were able to produce a thin wall between two microfluidic channels, which, upon excitation, can generate streaming fields that complement the acoustic radiation force and therefore can be utilised for trapping of bacteria. Our novel design robustly traps Escherichia coli at a flow rate of 10 μL min−1 and has a cell recovery performance of 47 ± 3% after washing the trapped cells. To verify that the performance of the medium exchange device is sufficient, we tested the electrocompetence of the recovered cells in a standard transformation procedure and found a transformation efficiency of 8 × 105 CFU per μg of plasmid DNA. Our device is a low-volume alternative to centrifugation-based methods and opens the door for miniaturisation of a plethora of microbiological and molecular engineering protocols.
A vibrating capillary for ultrasound rotation manipulation of zebrafish larvae
Zhang, Zhiyuan; Cao, Yilin; Caviglia, Sara; et al. (2024)
Lab on a Chip
Multifunctional micromanipulation systems have garnered significant attention due to the growing interest in biological and medical research involving model organisms like zebrafish (Danio rerio). Here, we report a novel acoustofluidic rotational micromanipulation system that offers rapid trapping, high-speed rotation, multi-angle imaging, and 3D model reconstruction of zebrafish larvae. An ultrasound-activated oscillatory glass capillary is used to trap and rotate a zebrafish larva. Simulation and experimental results demonstrate that both the vibrating mode and geometric placement of the capillary contribute to the developed polarized vortices along the long axis of the capillary. Given its capacities for easy-to-operate, stable rotation, avoiding overheating, and high-throughput manipulation, our system poses the potential to accelerate zebrafish-directed biomedical research.
Artificial bacterial flagella for micromanipulation
Zhang, Li; Peyer, Kathrin E.; Nelson, Bradley J. (2010)
Lab on a Chip
Multicomponent diffusion coefficients from microfluidics using Raman microspectroscopy
Peters, Christine; Wolff, Ludger; Haase, Sandra; et al. (2017)
Lab on a Chip
Diffusion is slow. Thus, diffusion experiments are intrinsically time-consuming and laborious. Additionally, the experimental effort is multiplied for multicomponent systems as the determination of multicomponent diffusion coefficients typically requires several experiments. To reduce the experimental effort, we present the first microfluidic diffusion measurement method for multicomponent liquid systems. The measurement setup combines a microfluidic chip with Raman microspectroscopy. Excellent agreement between experimental results and literature data is achieved for the binary system cyclohexane + toluene and the ternary system 1-propanol + 1-chlorobutane + heptane. The Fick diffusion coefficients are obtained from fitting a multicomponent convection-diffusion model to the mole fractions measured in experiments. Ternary diffusion coefficients can be obtained from a single experiment; high accuracy is already obtained from two experiments. Advantages of the presented measurement method are thus short measurement times, reduced sample consumption, and less experiments for the determination of a multicomponent diffusion coefficient.
Research Highlights
Dittrich, Petra S. (2008)
Lab on a Chip

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