scholarly journals Time-resolved imaging refractometry of microbicidal films using quantitative phase microscopy

2011 ◽  
Vol 16 (12) ◽  
pp. 120510 ◽  
Author(s):  
Matthew T. Rinehart ◽  
Tyler K. Drake ◽  
Francisco E. Robles ◽  
Lisa C. Rohan ◽  
David Katz ◽  
...  
Keyword(s):  
Time Resolved ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Time Resolved Imaging

scholarly journals Quantitative phase microscopy enables precise and efficient determination of biomolecular condensate composition

2020 ◽  
Author(s):  
Patrick M. McCall ◽  
Kyoohyun Kim ◽  
Anatol W. Fritsch ◽  
J.M. Iglesias-Artola ◽  
L.M. Jawerth ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Protein Concentration ◽  
Fluorescent Dyes ◽  
Basic Feature ◽  
Label Free ◽  
Time Resolved ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy

ABSTRACTMany compartments in eukaryotic cells are protein-rich biomolecular condensates demixed from the cyto- or nucleoplasm. Although much has been learned in recent years about the integral roles condensates play in many cellular processes as well as the biophysical properties of reconstituted condensates, an understanding of their most basic feature, their composition, remains elusive. Here we combined quantitative phase microscopy (QPM) and the physics of sessile droplets to develop a precise method to measure the shape and composition of individual model condensates. This technique does not rely on fluorescent dyes or tags, which we show can significantly alter protein phase behavior, and requires 1000-fold less material than traditional label-free technologies. We further show that this QPM method measures the protein concentration in condensates to a 3-fold higher precision than the next best label-free approach, and that commonly employed strategies based on fluorescence intensity dramatically underestimate these concentrations by as much as 50-fold. Interestingly, we find that condensed-phase protein concentrations can span a broad range, with PGL3, TAF15(RBD) and FUS condensates falling between 80 and 500 mg/ml under typical in vitro conditions. This points to a natural diversity in condensate composition specified by protein sequence. We were also able to measure temperature-dependent phase equilibria with QPM, an essential step towards relating phase behavior to the underlying physics and chemistry. Finally, time-resolved QPM reveals that PGL3 condensates undergo a contraction-like process during aging which leads to doubling of the internal protein concentration coupled to condensate shrinkage. We anticipate that this new approach will enable understanding the physical properties of biomolecular condensates and their function.

scholarly journals Characterization of Liposomes Using Quantitative Phase Microscopy (QPM)

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 590
Author(s):  
Jennifer Cauzzo ◽  
Nikhil Jayakumar ◽  
Balpreet Singh Ahluwalia ◽  
Azeem Ahmad ◽  
Nataša Škalko-Basnet
Keyword(s):  
Rapid Development ◽  
Fluorescent Labeling ◽  
Label Free ◽  
Batch Mode ◽  
Full Field ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Tracking Ability

The rapid development of nanomedicine and drug delivery systems calls for new and effective characterization techniques that can accurately characterize both the properties and the behavior of nanosystems. Standard methods such as dynamic light scattering (DLS) and fluorescent-based assays present challenges in terms of system’s instability, machine sensitivity, and loss of tracking ability, among others. In this study, we explore some of the downsides of batch-mode analyses and fluorescent labeling, while introducing quantitative phase microscopy (QPM) as a label-free complimentary characterization technique. Liposomes were used as a model nanocarrier for their therapeutic relevance and structural versatility. A successful immobilization of liposomes in a non-dried setup allowed for static imaging conditions in an off-axis phase microscope. Image reconstruction was then performed with a phase-shifting algorithm providing high spatial resolution. Our results show the potential of QPM to localize subdiffraction-limited liposomes, estimate their size, and track their integrity over time. Moreover, QPM full-field-of-view images enable the estimation of a single-particle-based size distribution, providing an alternative to the batch mode approach. QPM thus overcomes some of the drawbacks of the conventional methods, serving as a relevant complimentary technique in the characterization of nanosystems.

scholarly journals Efficient quantitative phase microscopy using programmable annular LED illumination

2017 ◽  
Vol 8 (10) ◽  
pp. 4687 ◽  
Author(s):  
Jiaji Li ◽  
Qian Chen ◽  
Jialin Zhang ◽  
Yan Zhang ◽  
Linpeng Lu ◽  
...  
Keyword(s):  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy

Direct full compensation of the aberrations in quantitative phase microscopy of thin objects by a single digital hologram

2007 ◽  
Vol 90 (4) ◽  
pp. 041104 ◽  
Author(s):  
L. Miccio ◽  
D. Alfieri ◽  
S. Grilli ◽  
P. Ferraro ◽  
A. Finizio ◽  
...  
Keyword(s):  
Quantitative Phase ◽  
Digital Hologram ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Full Compensation

scholarly journals Imaging red blood cell dynamics by quantitative phase microscopy

2008 ◽  
Vol 41 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Gabriel Popescu ◽  
YoungKeun Park ◽  
Wonshik Choi ◽  
Ramachandra R. Dasari ◽  
Michael S. Feld ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Dynamics ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy

scholarly journals Transcriptional, Electrophysiological, and Metabolic Characterizations of hESC-Derived First and Second Heart Fields Demonstrate a Potential Role of TBX5 in Cardiomyocyte Maturation

2021 ◽  
Vol 9 ◽  
Author(s):  
Arash Pezhouman ◽  
Ngoc B. Nguyen ◽  
Alexander J. Sercel ◽  
Thang L. Nguyen ◽  
Ali Daraei ◽  
...  
Keyword(s):  
Developmental Trajectory ◽  
Calcium Handling ◽  
Hesc Line ◽  
Functional Difference ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Quantitative Phase Microscopy ◽  
Atomic Force ◽  
Heart Field

Background: Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) can be used as a source for cell delivery to remuscularize the heart after myocardial infarction. Despite their therapeutic potential, the emergence of ventricular arrhythmias has limited their application. We previously developed a double reporter hESC line to isolate first heart field (FHF: TBX5+NKX2-5+) and second heart field (SHF: TBX5-NKX2-5+) CMs. Herein, we explore the role of TBX5 and its effects on underlying gene regulatory networks driving phenotypical and functional differences between these two populations.Methods: We used a combination of tools and techniques for rapid and unsupervised profiling of FHF and SHF populations at the transcriptional, translational, and functional level including single cell RNA (scRNA) and bulk RNA sequencing, atomic force and quantitative phase microscopy, respirometry, and electrophysiology.Results: Gene ontology analysis revealed three biological processes attributed to TBX5 expression: sarcomeric structure, oxidative phosphorylation, and calcium ion handling. Interestingly, migratory pathways were enriched in SHF population. SHF-like CMs display less sarcomeric organization compared to FHF-like CMs, despite prolonged in vitro culture. Atomic force and quantitative phase microscopy showed increased cellular stiffness and decreased mass distribution over time in FHF compared to SHF populations, respectively. Electrophysiological studies showed longer plateau in action potentials recorded from FHF-like CMs, consistent with their increased expression of calcium handling genes. Interestingly, both populations showed nearly identical respiratory profiles with the only significant functional difference being higher ATP generation-linked oxygen consumption rate in FHF-like CMs. Our findings suggest that FHF-like CMs display more mature features given their enhanced sarcomeric alignment, calcium handling, and decreased migratory characteristics. Finally, pseudotime analyses revealed a closer association of the FHF population to human fetal CMs along the developmental trajectory.Conclusion: Our studies reveal that distinguishing FHF and SHF populations based on TBX5 expression leads to a significant impact on their downstream functional properties. FHF CMs display more mature characteristics such as enhanced sarcomeric organization and improved calcium handling, with closer positioning along the differentiation trajectory to human fetal hearts. These data suggest that the FHF CMs may be a more suitable candidate for cardiac regeneration.

scholarly journals Spatial-Domain Low-Coherence Quantitative Phase Microscopy to Improve the Cytological Diagnosis of Pancreatic Cancer

2011 ◽  
Vol 140 (5) ◽  
pp. S-53 ◽  
Author(s):  
David A. Brokl ◽  
David Y. Lo ◽  
Walid E. Khalbuss ◽  
Pin Wang ◽  
Rajan K. Bista ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Spatial Domain ◽  
Cytological Diagnosis ◽  
Quantitative Phase ◽  
Phase Microscopy ◽  
Low Coherence ◽  
Quantitative Phase Microscopy
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