High-throughput label-free screening of euglena gracilis with optofluidic time-stretch quantitative phase microscopy

2017 ◽  
Author(s):  
Baoshan Guo ◽  
Cheng Lei ◽  
Takuro Ito ◽  
Yalikun Yaxiaer ◽  
Hirofumi Kobayashi ◽  
...  
Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 590
Author(s):  
Jennifer Cauzzo ◽  
Nikhil Jayakumar ◽  
Balpreet Singh Ahluwalia ◽  
Azeem Ahmad ◽  
Nataša Škalko-Basnet

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.


Lab on a Chip ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 75-82
Author(s):  
Yingdong Luo ◽  
Jinwu Yang ◽  
Xinqi Zheng ◽  
Jianjun Wang ◽  
Xin Tu ◽  
...  

We present real-time quantitative phase microscopy (RT-QPM) that can be used for on-chip three-dimensional visualization of droplets and high-throughput quantitative molecular measurement via real-time extraction of sample-induced phase variation.


2020 ◽  
Author(s):  
Patrick M. McCall ◽  
Kyoohyun Kim ◽  
Anatol W. Fritsch ◽  
J.M. Iglesias-Artola ◽  
L.M. Jawerth ◽  
...  

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.


Author(s):  
Björn Kemper ◽  
Arne Bokemeyer ◽  
Steffi Ketelhut ◽  
Lenz Philipp ◽  
Bettenworth Dominik

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Yair Rivenson ◽  
Tairan Liu ◽  
Zhensong Wei ◽  
Yibo Zhang ◽  
Kevin de Haan ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azeem Ahmad ◽  
Vishesh Dubey ◽  
Nikhil Jayakumar ◽  
Anowarul Habib ◽  
Ankit Butola ◽  
...  

AbstractHigh space-bandwidth product with high spatial phase sensitivity is indispensable for a single-shot quantitative phase microscopy (QPM) system. It opens avenue for widespread applications of QPM in the field of biomedical imaging. Temporally low coherence light sources are implemented to achieve high spatial phase sensitivity in QPM at the cost of either reduced temporal resolution or smaller field of view (FOV). In addition, such light sources have low photon degeneracy. On the contrary, high temporal coherence light sources like lasers are capable of exploiting the full FOV of the QPM systems at the expense of less spatial phase sensitivity. In the present work, we demonstrated that use of narrowband partially spatially coherent light source also called pseudo-thermal light source (PTLS) in QPM overcomes the limitations of conventional light sources. The performance of PTLS is compared with conventional light sources in terms of space bandwidth product, phase sensitivity and optical imaging quality. The capabilities of PTLS are demonstrated on both amplitude (USAF resolution chart) and phase (thin optical waveguide, height ~ 8 nm) objects. The spatial phase sensitivity of QPM using PTLS is measured to be equivalent to that for white light source and supports the FOV (18 times more) equivalent to that of laser light source. The high-speed capabilities of PTLS based QPM is demonstrated by imaging live sperm cells that is limited by the camera speed and large FOV is demonstrated by imaging histopathology human placenta tissue samples. Minimal invasive, high-throughput, spatially sensitive and single-shot QPM based on PTLS will enable wider penetration of QPM in life sciences and clinical applications.


Sign in / Sign up

Export Citation Format

Share Document