scholarly journals Label-free Viability Assay using Holographic Video Microscopy

2021 ◽  
Author(s):  
Mary Ann Odete ◽  
Rostislav Boltyanskiy ◽  
Fook Chiong Cheong ◽  
Laura Philips
Keyword(s):  
Cell Viability ◽  
Index Of Refraction ◽  
Yeast Cells ◽  
Blue Dye ◽  
Label Free ◽  
Particle Characterization ◽  
Viability Assay ◽  
Manual Counting ◽  
Traditional Approaches ◽  
Individual Particles

Abstract Total Holographic Characterization (THC) is presented here as an efficient, automated, label-free method of accurately identifying cell viability. THC is a single-particle characterization technology that determines the size and index of refraction of individual particles using the Lorenz-Mie theory of light scattering. Although assessment of cell viability is a challenge in many applications, including biologics manufacturing, traditional approaches often include unreliable labeling with dyes and/or time consuming methods of manually counting cells. In this work we measured the viability of Saccharomyces cerevisiae yeast in the presence of various concentrations of isopropanol as a function of time. All THC measurements were performed in the native environment of the sample with no dilution or addition of labels. We compared our results with THC to manual counting of living and dead cells as distinguished with trypan blue dye. Our findings demonstrate that THC can effectively distinguish living and dead yeast cells by the index of refraction of individual cells.

scholarly journals Label-free Viability Assay using Holographic Video Microscopy

2021 ◽  
Author(s):  
Mary Ann Odete ◽  
Rostislav Boltyanskiy ◽  
Fook Chiong Cheong ◽  
Laura Philips
Keyword(s):  
Cell Viability ◽  
Index Of Refraction ◽  
Yeast Cells ◽  
Blue Dye ◽  
Label Free ◽  
Particle Characterization ◽  
Viability Assay ◽  
Manual Counting ◽  
Traditional Approaches ◽  
Individual Particles

Abstract Total Holographic Characterization (THC) is presented here as an efficient, automated, label-free method of accurately identifying cell viability. THC is a single-particle characterization technology that determines the size and index of refraction of individual particles using the Lorenz-Mie theory of light scattering. Although assessment of cell viability is a challenge in many applications, including biologics manufacturing, traditional approaches often include unreliable labeling with dyes and/or time consuming methods of manually counting cells. In this work we measured the viability of Saccharomyces cerevisiae yeast in the presence of various concentrations of isopropanol as a function of time. All THC measurements were performed in the native environment of the sample with no dilution or addition of labels. We compared our results with THC to manual counting of living and dead cells as distinguished with trypan blue dye. Our findings demonstrate that THC can effectively distinguish living and dead yeast cells by the index of refraction of individual cells.

scholarly journals Label-free cell viability assay using phase imaging with computational specificity

2020 ◽  
Author(s):  
Chenfei Hu ◽  
Shenghua He ◽  
Young Jae Lee ◽  
Yuchen He ◽  
Edward M. Kong ◽  
...  
Keyword(s):  
Cell Viability ◽  
Hela Cells ◽  
Free Cell ◽  
Phase Imaging ◽  
Label Free ◽  
Cell Dynamics ◽  
Cell Viability Assay ◽  
Chemical Reagents ◽  
Viability Assay ◽  
Cell Staining

AbstractExisting approaches to evaluate cell viability involve cell staining with chemical reagents. However, this step of exogenous staining makes these methods undesirable for rapid, nondestructive and long term investigation. Here, we present instantaneous viability assessment of unlabeled cells using phase imaging with computation specificity (PICS). This new concept utilizes deep learning techniques to compute viability markers associated with the specimen measured by quantitative phase imaging. Demonstrated on HeLa cells culture, the proposed method reports approximately 95% accuracy in identifying injured and dead cells. Further comparison of cell morphology with labeled HeLa cells suggests that potential adverse effect on cell dynamics introduced by the viability reagents can be avoided using the label-free investigation method, which would be valuable for a broad range of biomedical applications.

Label-free cell viability assay using phase imaging with computational specificity (PICS)

2021 ◽  
Author(s):  
Chenfei Hu ◽  
Shenghua He ◽  
Young Jae Lee ◽  
Yuchen R. He ◽  
Mark Anastasio ◽  
...  
Keyword(s):  
Cell Viability ◽  
Free Cell ◽  
Phase Imaging ◽  
Label Free ◽  
Cell Viability Assay ◽  
Viability Assay

scholarly journals Evaporation-induced stimulation of bacterial osmoregulation for electrical assessment of cell viability

2016 ◽  
Vol 113 (26) ◽  
pp. 7059-7064 ◽  
Author(s):  
Aida Ebrahimi ◽  
Muhammad Ashraful Alam
Keyword(s):  
Cell Viability ◽  
Osmotic Pressure ◽  
Electrical Conductance ◽  
Ionic Concentration ◽  
Droplet Microfluidics ◽  
Cell Multiplication ◽  
Bacterial Cells ◽  
Label Free ◽  
The Road ◽  
Viability Assay

Bacteria cells use osmoregulatory proteins as emergency valves to respond to changes in the osmotic pressure of their external environment. The existence of these emergency valves has been known since the 1960s, but they have never been used as the basis of a viability assay to tell dead bacteria cells apart from live ones. In this paper, we show that osmoregulation provides a much faster, label-free assessment of cell viability compared with traditional approaches that rely on cell multiplication (growth) to reach a detectable threshold. The cells are confined in an evaporating droplet that serves as a dynamic microenvironment. Evaporation-induced increase in ionic concentration is reflected in a proportional increase of the droplet’s osmotic pressure, which in turn, stimulates the osmoregulatory response from the cells. By monitoring the time-varying electrical conductance of evaporating droplets, bacterial cells are identified within a few minutes compared with several hours in growth-based methods. To show the versatility of the proposed method, we show detection of WT and genetically modified nonhalotolerant cells (Salmonella typhimurium) and dead vs. live differentiation of nonhalotolerant (such as Escherichia coli DH5α) and halotolerant cells (such as Staphylococcus epidermidis). Unlike the growth-based techniques, the assay time of the proposed method is independent of cell concentration or the bacteria type. The proposed label-free approach paves the road toward realization of a new class of real time, array-formatted electrical sensors compatible with droplet microfluidics for laboratory on a chip applications.

Label-free cell viability assay using lens-free microscopy

2018 ◽  
Author(s):  
Cédric Allier ◽  
Thomas Bordy ◽  
Olivier Cioni ◽  
Lionel Hervé ◽  
Geoffrey Esteban ◽  
...  
Keyword(s):  
Cell Viability ◽  
Free Cell ◽  
Label Free ◽  
Cell Viability Assay ◽  
Viability Assay

THz Spectroscopy for a Rapid and Label-Free Cell Viability Assay in a Microfluidic Chip Based on an Optical Clearing Agent

2018 ◽  
Vol 91 (1) ◽  
pp. 785-791 ◽  
Author(s):  
Ke Yang ◽  
Xiang Yang ◽  
Xiang Zhao ◽  
Marc Lamy de la Chapelle ◽  
Weiling Fu
Keyword(s):  
Cell Viability ◽  
Microfluidic Chip ◽  
Free Cell ◽  
Thz Spectroscopy ◽  
Label Free ◽  
Cell Viability Assay ◽  
Optical Clearing ◽  
Viability Assay

Do We have a Satisfactory Cell Viability Assay? Review of the Currently Commercially-Available Assays

2020 ◽  
Vol 17 (1) ◽  
pp. 2-22 ◽  
Author(s):  
Abdel-Baset Halim
Keyword(s):  
Cell Viability ◽  
Data Interpretation ◽  
Positive Control ◽  
Live Cells ◽  
Proof Of Concept ◽  
Cell Viability Assay ◽  
Viability Assay ◽  
Current Cell ◽  
Dying Cells ◽  
Differential Permeability

:Cell-based assays are an important part of the drug discovery process and clinical research. One of the main hurdles is to design sufficiently robust assays with adequate signal to noise parameters while maintaining the inherent physiology of the cells and not interfering with the pharmacology of target being investigated.:A plethora of assays that assess cell viability (or cell heath in general) are commercially available and can be classified under different categories according to their concepts and principle of reactions. The assays are valuable tools, however, suffer from a large number of limitations. Some of these limitations can be procedural or operational, but others can be critical as those related to a poor concept or the lack of proof of concept of an assay, e.g. those relying on differential permeability of dyes in-and-out of viable versus compromised cell membranes. While the assays can differentiate between dead and live cells, most, if not all, of them can just assess the relative performance of cells rather than providing a clear distinction between healthy and dying cells. The possible impact of relatively high molecular weight dyes, used in most of the assay, on cell viability has not been addressed. More innovative assays are needed, and until better alternatives are developed, setup of current cell-based studies and data interpretation should be made with the limitations in mind. Negative and positive control should be considered whenever feasible. Also, researchers should use more than one orthogonal method for better assessment of cell health.

scholarly journals Promising biocompatible hydrogels of crosslinked polyelectrolytes for biomedical applications

2017 ◽  
Vol 3 (2) ◽  
pp. 695-698
Author(s):  
Andreas Brietzke ◽  
Christian von der Ehe ◽  
Sabine Illner ◽  
Claudia Matschegewski ◽  
Niels Grabow ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
Cell Viability ◽  
Biomedical Applications ◽  
High Potential ◽  
Cell Viability Assay ◽  
Mouse Fibroblasts ◽  
Viability Assay ◽  
Intelligent Implant ◽  
L929 Mouse

AbstractFor the development of intelligent implant systems hydrogels (HG) from crosslinked ionic liquids feature a high potential to be utilised as a drug depot. Biocompatibility of the HGs is one key prerequisite for biomedical applications. HGs were polymerised from a variety of different ionic monomers based on methacrylate, methacrylamide, styrene or vinyl imidazolium derivatives in aqueous solution. N,N'-methylenebisacrylamide was used as crosslinker. CellQuanti-Blue™ Cell Viability Assay Kit was implemented to proof viability of L929 mouse fibroblasts. The predominant part of the HG eluates generated only a marginal reduction of less than 15% cell viability at 100% eluate concentration. This underlines the excellent suitability of these HGs for biomedical applications and revealed some promising candidates for the development of drug depots for implants.

scholarly journals Sensitive cell viability assay for use in drug screens and for studying the mechanism of action of drugs inDictyostelium discoideum

BioTechniques ◽  
2006 ◽  
Vol 41 (5) ◽  
pp. 591-595 ◽  
Author(s):  
Junxia Min ◽  
Priya Sridevi ◽  
Stephen Alexander ◽  
Hannah Alexander
Keyword(s):  
Cell Viability ◽  
Mechanism Of Action ◽  
Sensitive Cell ◽  
Cell Viability Assay ◽  
Viability Assay
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