Application of a novel new multispectral nanoparticle tracking technique

McElfresh, Cameron; Harrington, Tyler; Vecchio, Kenneth S.

doi:10.1088/1361-6501/aab940

Cited by 14 publications

(16 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both instruments also have a capability to estimate nanoparticle concentration based on individual particle counting within the calibrated volume of sample. While the NanoSight uses only one laser source, the ViewSizer deploys three laser sources at different wavelengths, which generally improves both the size and concentration determinations of particles [55].…”

Section: A Residual Particle Populations In the Pure Water And Mastementioning

confidence: 99%

Light scattering by pure water and seawater: the depolarization ratio and its variation with salinity

et al. 2019

View full text Add to dashboard Cite

We measured the linearly polarized light scattering of pure water and seawater at various salinities and estimated the depolarization ratio using five different methods of data analysis after removing the scattering due to contamination by residual nanoparticles. The depolarization ratio values (δ) estimated for pure water using these different methods are largely consistent with each other and result in a mean value of 0.039 0.001. For seawater, our results reveal a trend of a slight linear increase of δ with salinity (S), δ 0.039 a 1 × S, where a 1 varies in the range of 1 × 10 −4 to 2 × 10 −4 between the methods.

show abstract

Section: A Residual Particle Populations In the Pure Water And Mastementioning

confidence: 99%

Light scattering by pure water and seawater: the depolarization ratio and its variation with salinity

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Offline instruments capable of immersion mode INP measurement include a number of droplet assays, in which sample suspensions are distributed among an array of droplets that are then cooled and frozen (e.g., Budke and Koop, 2015;Harrison et al, 2018;Hill et al, 2014;Whale et al, 2015) as well as other systems in which water is condensed onto particles collected on substrates prior to cooling and freezing (e.g., . As they are designed for analysis of liquid suspensions, droplet freezing assay techniques are commonly used for measurement of INPs suspended in precipitation (e.g., Creamean et al, 2019;Rangel-Alvarado et al, 2015;Michaud et al, 2014;Stopelli et al, 2014;Wright et al, 2014).…”

mentioning

confidence: 99%

Best practices for precipitation sample storage for offline studies of ice nucleation in marine and coastal environments

et al. 2020

View full text Add to dashboard Cite

Abstract. Ice-nucleating particles (INPs) are efficiently removed from clouds through precipitation, a convenience of nature for the study of these very rare particles that influence multiple climate-relevant cloud properties including ice crystal concentrations, size distributions and phase-partitioning processes. INPs suspended in precipitation can be used to estimate in-cloud INP concentrations and to infer their original composition. Offline droplet assays are commonly used to measure INP concentrations in precipitation samples. Heat and filtration treatments are also used to probe INP composition and size ranges. Many previous studies report storing samples prior to INP analyses, but little is known about the effects of storage on INP concentration or their sensitivity to treatments. Here, through a study of 15 precipitation samples collected at a coastal location in La Jolla, CA, USA, we found INP concentration changes up to > 1 order of magnitude caused by storage to concentrations of INPs with warm to moderate freezing temperatures (−7 to −19 ∘C). We compared four conditions: (1) storage at room temperature (+21–23 ∘C), (2) storage at +4 ∘C, (3) storage at −20 ∘C and (4) flash-freezing samples with liquid nitrogen prior to storage at −20 ∘C. Results demonstrate that storage can lead to both enhancements and losses of greater than 1 order of magnitude, with non-heat-labile INPs being generally less sensitive to storage regime, but significant losses of INPs smaller than 0.45 µm in all tested storage protocols. Correlations between total storage time (1–166 d) and changes in INP concentrations were weak across sampling protocols, with the exception of INPs with freezing temperatures ≥ −9 ∘C in samples stored at room temperature. We provide the following recommendations for preservation of precipitation samples from coastal or marine environments intended for INP analysis: that samples be stored at −20 ∘C to minimize storage artifacts, that changes due to storage are likely an additional uncertainty in INP concentrations, and that filtration treatments be applied only to fresh samples. At the freezing temperature −11 ∘C, average INP concentration losses of 51 %, 74 %, 16 % and 41 % were observed for untreated samples stored using the room temperature, +4, −20 ∘C, and flash-frozen protocols, respectively. Finally, the estimated uncertainties associated with the four storage protocols are provided for untreated, heat-treated and filtered samples for INPs between −9 and −17 ∘C.

show abstract

“…For NTA, the masking effect of larger particles over smaller ones has been well documented: Tian et al could not achieve simultaneous measurement of 100 and 1000 nm bead mixtures or 100 and 300 nm bead mixtures, and in mixtures of 100 and 200 nm beads, Krueger et al observed a clear bias toward the larger species at all tested ratios . In 2018, McElfresh et al demonstrated that MNTA could address this limitation and accurately measured multimodal mixtures of gold and polystyrene latex particles . One unresolved question was its utility for soft materialsespecially those that undergo size dynamics such as aggregating proteins.…”

mentioning

confidence: 99%

Multispectral Nanoparticle Tracking Analysis for the Real-Time and Label-Free Characterization of Amyloid-β Self-Assembly In Vitro

et al. 2020

View full text Add to dashboard Cite

The deposition of amyloid β (Aβ) plaques and fibrils in the brain parenchyma is a hallmark of Alzheimer’s disease (AD), but a mechanistic understanding of the role Aβ plays in AD has remained unclear. One important reason could be the limitations of current tools to size and count Aβ fibrils in real time. Conventional techniques from molecular biology largely use ensemble averaging; some microscopy analyses have been reported but suffer from low throughput. Nanoparticle tracking analysis is an alternative approach developed in the past decade for sizing and counting particles according to their Brownian motion; however, it is limited in sensitivity to polydisperse solutions because it uses only one laser. More recently, multispectral nanoparticle tracking analysis (MNTA) was introduced to address this limitation; it uses three visible wavelengths to quantitate heterogeneous particle distributions. Here, we used MNTA as a label-free technique to characterize the in vitro kinetics of Aβ1–42 aggregation by measuring the size distributions of aggregates during self-assembly. Our results show that this technology can monitor the aggregation of 106–108 particles/mL with a temporal resolution between 15 and 30 min. We corroborated this method with the fluorescent Thioflavin-T assay and transmission electron microscopy (TEM), showing good agreement between the techniques (Pearson’s r = 0.821, P < 0.0001). We also used fluorescent gating to examine the effect of ThT on the aggregate size distribution. Finally, the biological relevance was demonstrated via fibril modulation in the presence of a polyphenolic Aβ disruptor. In summary, this approach measures Aβ assembly similar to ensemble-type measurements but with per-fibril resolution.

show abstract

Application of a novel new multispectral nanoparticle tracking technique

Cited by 14 publications

References 37 publications

Light scattering by pure water and seawater: the depolarization ratio and its variation with salinity

Light scattering by pure water and seawater: the depolarization ratio and its variation with salinity

Best practices for precipitation sample storage for offline studies of ice nucleation in marine and coastal environments

Multispectral Nanoparticle Tracking Analysis for the Real-Time and Label-Free Characterization of Amyloid-β Self-Assembly In Vitro

Contact Info

Product

Resources

About