A New Integrated Lab-on-a-Chip System for Fast Dynamic Study of Mammalian Cells under Physiological Conditions in Bioreactor

Abstract

For the quantitative analysis of cellular metabolism and its dynamics it is essential to achieve rapid sampling, fast quenching of metabolism and the removal of extracellular metabolites. Common manual sample preparation methods and protocols for cells are time-consuming and often lead to the loss of physiological conditions. In this work, we present a microchip-bioreactor setup which provides an integrated and rapid sample preparation of mammalian cells. The lab-on-a-chip system consists of five connected units that allow sample treatment, mixing and incubation of the cells, followed by cell separation and simultaneous exchange of media within seconds. This microsystem is directly integrated into a bioreactor for mammalian cell cultivation. By applying overpressure (2 bar) onto the bioreactor, this setup allows pulsation free, defined, fast, and continuous sampling. Experiments evince that Chinese Hamster Ovary cells (CHO-K1) can be separated from the culture broth and transferred into a new medium efficiently. Furthermore, this setup permits the treatment of cells for a defined time (9 s or 18 s) which can be utilized for pulse experiments, quenching of cell metabolism, and/or another defined chemical treatment. Proof of concept experiments were performed using glutamine containing medium for pulse experiments. Continuous sampling of cells showed a high reproducibility over a period of 18 h.

Sunlight-Activated Propidium Monoazide Pretreatment for Differentiation of Viable and Dead Bacteria by Quantitative Real-Time Polymerase Chain Reaction

“…A well-designed LOAC device can provide thorough mixing for the PMA and treated sample and control the time for dark incubation and light exposure. 40,41 In addition, a light concentration unit can be integrated to enhance the sunlight intensity when it is needed. Multiple sequential treatments can also be realized on a LOAC device by repeating the treatment unit.…”

“…The results of this study showed that the sunlight-activated PMA pretreatment could be easily integrated onto a LOAC device for off-the-grid microbial detection and quantification. A well-designed LOAC device can provide thorough mixing for the PMA and treated sample and control the time for dark incubation and light exposure. , In addition, a light concentration unit can be integrated to enhance the sunlight intensity when it is needed. Multiple sequential treatments can also be realized on a LOAC device by repeating the treatment unit.…”

In search of an effective cell disruption method to isolate intact mitochondria from Chinese hamster ovary cells

“…Permeabilized cells kept a spherical form while releasing the cytoplasm (cell ghosts). This feature could be utilized for a micro scale application (Lab‐on‐a‐Chip) in order to obtain a rapid cell permeabilization and a subsequent separation of cytosol and cell ghosts containing intact mitochondria .…”

Breakthroughs in Photonics 2013: Quantitative Phase Imaging: Metrology Meets Biology

“…In recent years, lab-on-a-chip microfluidic devices [22], typically built upon silicon wafers, have gained popularity for studying intracellular processes and functionalities [23], [24], drug screening [25], [26], and bio-sensing [27]. On the other hand, QPI, a highly sensitive technique in both spatial and temporal dimensions, has been widely used in biological imaging, due to its label-free and high throughput nature.…”