Methods and applications of label-free cell-based systems

Label-free monitoring of living cells is used in various applications such as drug development, toxicology, regenerative medicine or environmental monitoring. The most prominent methods for monitoring the extracellular acidification, oxygen consumption, electrophysiological activity and morphological changes of living cells are described. Furthermore, the intelligent mobile lab (IMOLA) – a computer controlled system integrating cell monitoring and automated cell cultivation – is described as an example of a cell-based system for microphysiometry. Results from experiments in the field of environmental monitoring using algae are presented. An outlook toward the development of an organ-on-chip technology is given.

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Pinhole microLED Array as Point Source Illumination for Miniaturized Lensless Cell Monitoring Systems

Proceedings ◽

10.3390/proceedings2130866 ◽

2018 ◽

Vol 2 (13) ◽

pp. 866 ◽

Cited By ~ 1

Author(s):

Shinta Mariana ◽

Gregor Scholz ◽

Feng Yu ◽

Agus Budi Dharmawan ◽

Iqbal Syamsu ◽

...

Keyword(s):

Image Quality ◽

Light Emitting Diode ◽

Free Cell ◽

Monitoring Systems ◽

Label Free ◽

Light Emitting ◽

Non Invasive ◽

Cell Monitoring ◽

Blue Spectral Region ◽

Led Arrays

Pinhole‐shaped light‐emitting diode (LED) arrays with dimension ranging from 100 μm down to 5 μm have been developed as point illumination sources. The proposed microLED arrays, which are based on gallium nitride (GaN) technology and emitting in the blue spectral region (λ = 465 nm), are integrated into a compact lensless holographic microscope for a non‐invasive, label‐free cell sensing and imaging. From the experimental results using single pinhole LEDs having a diameter of 90 μm, the reconstructed images display better resolution and enhanced image quality compared to those captured using a commercial surface‐mount device (SMD)‐based LED.

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The potential of autofluorescence for the detection of single living cells for label-free cell sorting in microfluidic systems

Electrophoresis ◽

10.1002/elps.200406070 ◽

2004 ◽

Vol 25 (21-22) ◽

pp. 3740-3745 ◽

Cited By ~ 28

Author(s):

Jurjen Emmelkamp ◽

Floor Wolbers ◽

Helene Andersson ◽

Ralph S. DaCosta ◽

Brian C. Wilson ◽

...

Keyword(s):

Cell Sorting ◽

Free Cell ◽

Living Cells ◽

Label Free ◽

Microfluidic Systems ◽

Single Living Cells ◽

Single Living

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Impedance spectroscopy flow cytometry: On-chip label-free cell differentiation

Cytometry Part A ◽

10.1002/cyto.a.20141 ◽

2005 ◽

Vol 65A (2) ◽

pp. 124-132 ◽

Cited By ~ 268

Author(s):

Karen Cheung ◽

Shady Gawad ◽

Philippe Renaud

Keyword(s):

Flow Cytometry ◽

Cell Differentiation ◽

Impedance Spectroscopy ◽

Free Cell ◽

Label Free ◽

On Chip

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MICRO-SCALE TECHNOLOGIES FOR CELL MECHANICS: EXPERIMENTAL AND MODELLING APPROACHES

Istituto Lombardo - Accademia di Scienze e Lettere - Incontri di Studio ◽

10.4081/incontri.2018.388 ◽

2018 ◽

Author(s):

Federica Caselli ◽

Nicola A. Nodargi ◽

Paolo Bisegna

Keyword(s):

Cell Mechanics ◽

Cell Biology ◽

Single Cell Level ◽

Mechanical Function ◽

Label Free ◽

Cell Level ◽

Lab On Chip ◽

Non Invasive ◽

Chip Technology ◽

On Chip

Cell mechanics is a discipline that bridges cell biology with mechanics. Emerging microscale technologies are opening new venues in the field, due to their costeffectiveness, relatively easy fabrication, and high throughput. Two examples of those technologies are discussed here: microfluidic impedance cytometry and erythrocyte electrodeformation. The former is a lab-on-chip technology offering a simple, non-invasive, label-free method for counting, identifying and monitoring cellular biophysical and mechanical function at the single-cell level. The latter is a useful complement to the former, enabling cell deformation under the influence of an applied electric field.

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Synchrotron multimodal imaging in a whole cell reveals lipid droplet core organization

Journal of Synchrotron Radiation ◽

10.1107/s1600577520003847 ◽

2020 ◽

Vol 27 (3) ◽

pp. 772-778 ◽

Cited By ~ 1

Author(s):

Frédéric Jamme ◽

Bertrand Cinquin ◽

Yann Gohon ◽

Eva Pereiro ◽

Matthieu Réfrégiers ◽

...

Keyword(s):

Lipid Droplet ◽

Neutral Lipids ◽

Imaging Techniques ◽

Living Cells ◽

Label Free ◽

Steryl Esters ◽

A Cell ◽

Deep Ultraviolet ◽

Auto Fluorescence ◽

Chemical Contents

A lipid droplet (LD) core of a cell consists mainly of neutral lipids, triacylglycerols and/or steryl esters (SEs). The structuration of these lipids inside the core is still under debate. Lipid segregation inside LDs has been observed but is sometimes suggested to be an artefact of LD isolation and chemical fixation. LD imaging in their native state and in unaltered cellular environments appears essential to overcome these possible technical pitfalls. Here, imaging techniques for ultrastructural study of native LDs in cellulo are provided and it is shown that LDs are organized structures. Cryo soft X-ray tomography and deep-ultraviolet (DUV) transmittance imaging are showing a partitioning of SEs at the periphery of the LD core. Furthermore, DUV transmittance and tryptophan/tyrosine auto-fluorescence imaging on living cells are combined to obtain complementary information on cell chemical contents. This multimodal approach paves the way for a new label-free organelle imaging technique in living cells.

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2D Label Free Microscopy Imaging Analysis Using Machine Learning

Electronic Imaging ◽

10.2352/issn.2470-1173.2020.14.coimg-341 ◽

2020 ◽

Vol 2020 (14) ◽

pp. 341-1-341-10

Author(s):

Han Hu ◽

Yang Lei ◽

Daisy Xin ◽

Viktor Shkolnikov ◽

Steven Barcelo ◽

...

Keyword(s):

Machine Learning ◽

Free Cell ◽

Living Cells ◽

Training Data ◽

Learning Approaches ◽

Label Free ◽

Imaging Analysis ◽

Microscopy Imaging ◽

Limited Availability ◽

Free Cells

Separation and isolation of living cells plays an important role in the fields of medicine and biology with label-free imaging often used for isolating cells. The analysis of label-free cell images has many challenges when examining the behavior of cells. This paper presents methods to analyze label-free cells. Many of the tools we describe are based on machine learning approaches. We also investigate ways of augmenting limited availability of training data. Our results demonstrate that our proposed methods are capable of successfully segmenting and classifying label-free cells.

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Intracellular hydrion concentration studies. V.-Colorimetric p H of malignant cells in tissue culture

Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character ◽

10.1098/rspb.1932.0015 ◽

1932 ◽

Vol 110 (765) ◽

pp. 120-124 ◽

Cited By ~ 8

Keyword(s):

Morphological Changes ◽

Surrounding Medium ◽

Living Cells ◽

Acid Dye ◽

Acid Dyes ◽

Sodium Salts ◽

Somatic Tissues ◽

Mammalian Tissues ◽

A Cell ◽

Hydrion Concentration

The microinjection of the relatively small of mammalian tissues offers considerable difficulties, the chief of which is some means of knowing whether the cell in still alive after the injection. Usually deterioration of the cell is made evident by easily recognisable morphological changes, but this is not always the case. The best criterion so far encountered for the injection of solutions of dyes is the restriction of the color to the cell injection. This is more difficult to judge with dyes, especially those basic in nature, which easily penetrate cells from without. In such cases special pains must be taken to prevent spilling into the medium during the time that the pipette is being brought into the cell to be injected. Fortunately, the Clark and Lubs indicators are sodium salts of acid dyes, and most of these penetrate living cells, either very slowly or not at all. The consequence is that a small amount accidentally spilled about the cells quickly fades away by diffusion into the surrounding medium and does not disturb the procedure of injection. When once a solution of an acid dye is injected into a cell, the acquired colour persists for an appreciable length of time. Up to the present, the injection of cells of somatic tissues has always been followed, generally within 5 to 15 minutes, by observable signs of cytolysis. This is accompanied, and frequently preceded, by a fading out of the colour of the injected dye. From these observations it has been assumed that the cell is alive as long as the indicator is still within the cell injected. This assumption is supported by experiments on marine ova (Needham, 1926), for they have been demonstrated to be alive while retaining the colour of the injected indicator both in the cytoplasm and in the nucleus (Chambers and Pollack, 1927).

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