Infrared Microspectroscopy of Live Cells in Microfluidic Devices (MD-IRMS): Toward a Powerful Label-Free Cell-Based Assay

2012 ◽  
Vol 84 (11) ◽  
pp. 4768-4775 ◽  
Author(s):  
L. Vaccari ◽  
G. Birarda ◽  
L. Businaro ◽  
S. Pacor ◽  
G. Grenci
Keyword(s):  
Microfluidic Devices ◽  
Free Cell ◽  
Live Cells ◽  
Label Free ◽  
Infrared Microspectroscopy

Label Free Cell Purification Following Electroporation

2020 ◽  
Author(s):  
Beth Ringwelski ◽  
Vidura Jayasooriya ◽  
Dharmakeerthi Nawarathna
Keyword(s):  
T Cells ◽  
T Cell ◽  
Free Cell ◽  
Live Cells ◽  
Label Free ◽  
Car T Cell ◽  
Viable Solution ◽  
Car T ◽  
Cell Sample ◽  
Apoptosis And Necrosis

Abstract Cell transfection by electroporation is a biological assay that has been utilized to inject exogenous molecules (e.g.: RNA, DNA and protein) into live cells. Recently, electroporation has been utilized in developing cell therapy for cancer (e.g., CAR T-cell). One of the major drawbacks in current electroporation methods is the cell death during the process. These dead cells can be detrimental, if injected back to the patients. Current cell filtering methods are unable purify T-cells following electroporation, this is due to the lack of unique biomarkers that target the apoptosis and necrosis of T-cells. To address this issue, we have developed a method using dielectrophoresis and microfluidics, where no prior labeling is needed to isolate dead cells from live cells. Upon electroporation, the cell sample has to be flowed through the microfluidic chip where a selective electric field is applied through specially designed electrodes so that the dead cells are trapped on the electrodes, and the live cells are able to flow through and are collected at the end. Results after purification of the cells using our method reveal that it is possible to achieve ∼100% of purity in filtering of the live cells. This method presents a viable solution to a critical concern regarding CAR T-cell manufacturing. This paper presents an extended study of the variation of efficacy in the design with the time from the electroporation.

scholarly journals Utilizing Stimulated Raman Scattering Microscopy To Study Intracellular Distribution of Label-Free Ponatinib in Live Cells

2019 ◽  
Vol 63 (5) ◽  
pp. 2028-2034 ◽  
Author(s):  
Kristel Sepp ◽  
Martin Lee ◽  
Marie T. J. Bluntzer ◽  
G. Vignir Helgason ◽  
Alison N. Hulme ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Stimulated Raman Scattering ◽  
Intracellular Distribution ◽  
Live Cells ◽  
Label Free ◽  
Stimulated Raman

Label-free cell phenotypic study of opioid receptors and discovery of novel mu opioid ligands from natural products

2021 ◽  
Vol 270 ◽  
pp. 113872
Author(s):  
Tao Hou ◽  
Fangfang Xu ◽  
Xingrong Peng ◽  
Han Zhou ◽  
Xiuli Zhang ◽  
...  
Keyword(s):  
Natural Products ◽  
Opioid Receptors ◽  
Free Cell ◽  
Label Free ◽  
Mu Opioid ◽  
Opioid Ligands

scholarly journals Microfluidic Tools for Enhanced Characterization of Therapeutic Stem Cells and Prediction of Their Potential Antimicrobial Secretome

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 750
Author(s):  
Pasquale Marrazzo ◽  
Valeria Pizzuti ◽  
Silvia Zia ◽  
Azzurra Sargenti ◽  
Daniele Gazzola ◽  
...  
Keyword(s):  
Stem Cells ◽  
Defense Mechanisms ◽  
Live Cells ◽  
Label Free ◽  
Bacterial Diseases ◽  
Prospective Application ◽  
Therapy Strategies ◽  
Stromal Stem Cells ◽  
Different Sources

Antibiotic resistance is creating enormous attention on the development of new antibiotic-free therapy strategies for bacterial diseases. Mesenchymal stromal stem cells (MSCs) are the most promising candidates in current clinical trials and included in several cell-therapy protocols. Together with the well-known immunomodulatory and regenerative potential of the MSC secretome, these cells have shown direct and indirect anti-bacterial effects. However, the low reproducibility and standardization of MSCs from different sources are the current limitations prior to the purification of cell-free secreted antimicrobial peptides and exosomes. In order to improve MSC characterization, novel label-free functional tests, evaluating the biophysical properties of the cells, will be advantageous for their cell profiling, population sorting, and quality control. We discuss the potential of emerging microfluidic technologies providing new insights into density, shape, and size of live cells, starting from heterogeneous or 3D cultured samples. The prospective application of these technologies to studying MSC populations may contribute to developing new biopharmaceutical strategies with a view to naturally overcoming bacterial defense mechanisms.

Raman spectroscopy-based label-free cell identification using wavelet transform and support vector machine

RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 50027-50033 ◽  
Author(s):  
S. Bakhtiaridoost ◽  
H. Habibiyan ◽  
S. Muhammadnejad ◽  
M. Haddadi ◽  
H. Ghafoorifard ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Raman Spectroscopy ◽  
Wavelet Transform ◽  
Raman Spectra ◽  
Free Cell ◽  
Support Vector ◽  
Label Free ◽  
Cell Identification ◽  
Rare Cells

Wavelet transform and SVM applied to Raman spectra makes a powerful and accurate tool for identification of rare cells such as CTCs.

scholarly journals Nanoscale chromatin imaging and analysis platform bridges 4D chromatin organization with molecular function

2021 ◽  
Vol 7 (1) ◽  
pp. eabe4310
Author(s):  
Yue Li ◽  
Adam Eshein ◽  
Ranya K.A. Virk ◽  
Aya Eid ◽  
Wenli Wu ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Super Resolution ◽  
Population Level ◽  
Average Diameter ◽  
Live Cells ◽  
Molecular Function ◽  
Label Free ◽  
Multiple Length Scales ◽  
Chromatin Packing ◽  
Analysis Platform

Extending across multiple length scales, dynamic chromatin structure is linked to transcription through the regulation of genome organization. However, no individual technique can fully elucidate this structure and its relation to molecular function at all length and time scales at both a single-cell level and a population level. Here, we present a multitechnique nanoscale chromatin imaging and analysis (nano-ChIA) platform that consolidates electron tomography of the primary chromatin fiber, optical super-resolution imaging of transcription processes, and label-free nano-sensing of chromatin packing and its dynamics in live cells. Using nano-ChIA, we observed that chromatin is localized into spatially separable packing domains, with an average diameter of around 200 nanometers, sub-megabase genomic size, and an internal fractal structure. The chromatin packing behavior of these domains exhibits a complex bidirectional relationship with active gene transcription. Furthermore, we found that properties of PDs are correlated among progenitor and progeny cells across cell division.

A ‘smart’ aptamer-functionalized continuous label-free cell catch-transport-release system

2021 ◽  
Author(s):  
Bozhen Zhang ◽  
Canran Wang ◽  
Yingjie Du ◽  
Rebecca Paxton ◽  
Ximin He
Keyword(s):  
Biomedical Research ◽  
Cell Sorting ◽  
Free Cell ◽  
Label Free ◽  
Clinical Therapeutics ◽  
Release System ◽  
System P

Label-free cell sorting devices are of great significance for biomedical research and clinical therapeutics. However, current platforms for label-free cell sorting cannot achieve continuity and selectivity simultaneously, resulting in complex...

scholarly journals Label-Free Digital Holo-tomographic Microscopy Reveals Virus-Induced Cytopathic Effects in Live Cells

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Artur Yakimovich ◽  
Robert Witte ◽  
Vardan Andriasyan ◽  
Fanny Georgi ◽  
Urs F. Greber
Keyword(s):  
Refractive Index ◽  
Vaccinia Virus ◽  
Virus Type ◽  
Live Cells ◽  
Refractive Index Gradient ◽  
Label Free ◽  
Virus Infections ◽  
Cytopathic Effects ◽  
Infected Cells ◽  
Index Gradient

ABSTRACTCytopathic effects (CPEs) are a hallmark of infections. CPEs are difficult to observe due to phototoxicity from classical light microscopy. We report distinct patterns of virus infections in live cells using digital holo-tomographic microscopy (DHTM). DHTM is label-free and records the phase shift of low-energy light passing through the specimen on a transparent surface with minimal perturbation. DHTM measures the refractive index (RI) and computes the refractive index gradient (RIG), unveiling optical heterogeneity in cells. We find that vaccinia virus (VACV), herpes simplex virus (HSV), and rhinovirus (RV) infections progressively and distinctly increased RIG. VACV infection, but not HSV and RV infections, induced oscillations of cell volume, while all three viruses altered cytoplasmic membrane dynamics and induced apoptotic features akin to those caused by the chemical compound staurosporine. In sum, we introduce DHTM for quantitative label-free microscopy in infection research and uncover virus type-specific changes and CPE in living cells with minimal interference.IMPORTANCEThis study introduces label-free digital holo-tomographic microscopy (DHTM) and refractive index gradient (RIG) measurements of live, virus-infected cells. We use DHTM to describe virus type-specific cytopathic effects, including cyclic volume changes of vaccinia virus infections, and cytoplasmic condensations in herpesvirus and rhinovirus infections, distinct from apoptotic cells. This work shows for the first time that DHTM is suitable to observe virus-infected cells and distinguishes virus type-specific signatures under noninvasive conditions. It provides a basis for future studies, where correlative fluorescence microscopy of cell and virus structures annotate distinct RIG values derived from DHTM.

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