scholarly journals Hyperspectral Counting of Multiplexed Nanoparticle Emitters in Single Cells and Organelles

2021 ◽  
Author(s):  
Prakrit V Jena ◽  
Mitchell A Gravely ◽  
Christian Cupo ◽  
Mohammad Moein Safaee ◽  
Daniel Roxbury ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Single Cell ◽  
Single Cells ◽  
Cellular Structures ◽  
Live Cells ◽  
Tissue Cell ◽  
Significant Heterogeneity ◽  
The Subject ◽  
Non Gaussian ◽  
Accurate Quantification

Nanomaterials are the subject of a range of biomedical, commercial, and environmental investigations involving measurements in living cells and tissues. Accurate quantification of nanomaterials, at the tissue, cell, and organelle levels, is often difficult, however, in part due to their inhomogeneity. Here, we propose a method that uses the diverse optical properties of a nanomaterial preparation in order to improve quantification at the single-cell and organelle level. We developed 'hyperspectral counting', which employs diffraction-limited imaging via hyperspectral microscopy of a diverse set of nanomaterial emitters, to estimate nanomaterial counts in live cells and sub-cellular structures. A mathematical model was developed, and Monte Carlo simulations were employed, to improve the accuracy of these estimates, enabling quantification with single-cell and single-endosome resolution. We applied this nanometrology technique to identify an upper-limit of the rate of uptake into cells -approximately 3,000 particles endocytosed within 30 minutes. In contrast, conventional ROI counting results in a 230% undercount. The method identified significant heterogeneity and a broad non-Gaussian distribution of carbon nanotube uptake within cells. For example, while a particular cell contained an average of 1 nanotube per endosome, the heterogenous distribution resulted in over 7 nanotubes localizing within some endosomes, substantially changing the accounting of subcellular nanoparticle concentration distributions. This work presents a method to quantify cellular and subcellular concentrations of a heterogeneous carbon nanotube reference material, with implications for nanotoxicology, drug/gene delivery, and nanosensor fields.

scholarly journals ZipSeq : Barcoding for Real-time Mapping of Single Cell Transcriptomes

2020 ◽  
Author(s):  
Kenneth H. Hu ◽  
John P. Eichorst ◽  
Chris S. McGinnis ◽  
David M. Patterson ◽  
Eric D. Chow ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Real Time ◽  
Dimensional Space ◽  
Single Cells ◽  
Expression Patterns ◽  
Live Cells ◽  
Glass Substrates ◽  
Complete Mapping

ABSTRACTSpatial transcriptomics seeks to integrate single-cell transcriptomic data within the 3-dimensional space of multicellular biology. Current methods use glass substrates pre-seeded with matrices of barcodes or fluorescence hybridization of a limited number of probes. We developed an alternative approach, called ‘ZipSeq’, that uses patterned illumination and photocaged oligonucleotides to serially print barcodes (Zipcodes) onto live cells within intact tissues, in real-time and with on-the-fly selection of patterns. Using ZipSeq, we mapped gene expression in three settings: in-vitro wound healing, live lymph node sections and in a live tumor microenvironment (TME). In all cases, we discovered new gene expression patterns associated with histological structures. In the TME, this demonstrated a trajectory of myeloid and T cell differentiation, from periphery inward. A variation of ZipSeq efficiently scales to the level of single cells, providing a pathway for complete mapping of live tissues, subsequent to real-time imaging or perturbation.

scholarly journals Mapping Protein Numbers in Living Cells

2021 ◽  
Author(s):  
Derek J Thirstrup ◽  
Jie Yao ◽  
Jamie Sherman ◽  
Irina A Mueller ◽  
Winfried Wiegraebe
Keyword(s):  
Single Cell ◽  
Laser Scanning ◽  
Light Sheet ◽  
Living Cells ◽  
Cellular Protein ◽  
Cellular Structures ◽  
Live Cells ◽  
Total Proteins ◽  
Cell Gene Expression ◽  
Induced Pluripotent

We introduce a new, robust method to map the numbers of proteins in living cells. The method can be applied to laser scanning, spinning disk, and lattice light-sheet microscopes in a robust, reproducible, and scalable fashion. The method uses calibrated EGFP solutions that are imaged with the appropriate microscope modality to create a calibration curve that is then applied to convert the fluorescence intensities from 3D microscope images into molecule numbers. We applied this method to human induced pluripotent stem cells in which proteins representing key cellular structures were endogenously tagged with mEGFP. We used the ratio of mEGFP-tagged proteins to total proteins to create 3D maps of live cells showing the density of total proteins measured in molecules per µm3. The method opens the door to new quantitative single cell analyses of cellular protein numbers in the context of single cell gene expression, associations with cellular complexes, and changes in cellular behaviors. The method is capable of quantifying protein numbers, over three orders of magnitude, in the cytoplasm or within various cellular structures while offering the unique advantages of each microscopy modality.

scholarly journals Patterning of Particles and Live Cells at Single Cell Resolution

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 505
Author(s):  
Adar Hacohen ◽  
Hadass R. Jessel ◽  
Alon Richter-Levin ◽  
Orit Shefi
Keyword(s):  
Single Cell ◽  
Dna Sequences ◽  
Single Cells ◽  
Experimental Methods ◽  
Live Cells ◽  
File Format ◽  
Biological Engineering ◽  
Single Particles ◽  
Quantitative Measurements ◽  
Different Types

The ability to manipulate and selectively position cells into patterns or distinct microenvironments is an important component of many single cell experimental methods and biological engineering applications. Although a variety of particles and cell patterning methods have been demonstrated, most of them deal with the patterning of cell populations, and are either not suitable or difficult to implement for the patterning of single cells. Here, we describe a bottom-up strategy for the micropatterning of cells and cell-sized particles. We have configured a micromanipulator system, in which a pneumatic microinjector is coupled to a holding pipette capable of physically isolating single particles and cells from different types, and positioning them with high accuracy in a predefined position, with a resolution smaller than 10 µm. Complementary DNA sequences were used to stabilize and hold the patterns together. The system is accurate, flexible, and easy-to-use, and can be automated for larger-scale tasks. Importantly, it maintains the viability of live cells. We provide quantitative measurements of the process and offer a file format for such assemblies.

scholarly journals High-throughput label-free molecular fingerprinting flow cytometry

2019 ◽  
Vol 5 (1) ◽  
pp. eaau0241 ◽  
Author(s):  
Kotaro Hiramatsu ◽  
Takuro Ideguchi ◽  
Yusuke Yonamine ◽  
SangWook Lee ◽  
Yizhi Luo ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Single Cell ◽  
High Throughput ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Fluorescent Labeling ◽  
Live Cells ◽  
Molecular Fingerprinting ◽  
Label Free ◽  
Indispensable Tool

Flow cytometry is an indispensable tool in biology for counting and analyzing single cells in large heterogeneous populations. However, it predominantly relies on fluorescent labeling to differentiate cells and, hence, comes with several fundamental drawbacks. Here, we present a high-throughput Raman flow cytometer on a microfluidic chip that chemically probes single live cells in a label-free manner. It is based on a rapid-scan Fourier-transform coherent anti-Stokes Raman scattering spectrometer as an optical interrogator, enabling us to obtain the broadband molecular vibrational spectrum of every single cell in the fingerprint region (400 to 1600 cm−1) with a record-high throughput of ~2000 events/s. As a practical application of the method not feasible with conventional flow cytometry, we demonstrate high-throughput label-free single-cell analysis of the astaxanthin productivity and photosynthetic dynamics ofHaematococcus lacustris.

scholarly journals Pairing Microwell Arrays with an Affordable, Semiautomated Single-Cell Aspirator for the Interrogation of Circulating Tumor Cell Heterogeneity

2020 ◽  
Vol 25 (2) ◽  
pp. 162-176
Author(s):  
Jacob J. Tokar ◽  
Charlotte N. Stahlfeld ◽  
Jamie M. Sperger ◽  
David J. Niles ◽  
David J. Beebe ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Single Cell ◽  
Single Cells ◽  
Rna Extraction ◽  
Circulating Tumor Cell ◽  
Bulk Sample ◽  
Live Cells ◽  
Target Cells ◽  
Castration Resistant Prostate Cancer ◽  
Background Population

Comprehensive analysis of tumor heterogeneity requires robust methods for the isolation and analysis of single cells from patient samples. An ideal approach would be fully compatible with downstream analytic methods, such as advanced genomic testing. These endpoints necessitate the use of live cells at high purity. A multitude of microfluidic circulating tumor cell (CTC) enrichment technologies exist, but many of those perform bulk sample enrichment and are not, on their own, capable of single-cell interrogation. To address this, we developed an affordable semiautomated single-cell aspirator (SASCA) to further enrich rare-cell populations from a specialized microwell array, per their phenotypic markers. Immobilization of cells within microwells, integrated with a real-time image processing software, facilitates the detection and precise isolation of targeted cells that have been optimally seeded into the microwells. Here, we demonstrate the platform capabilities through the aspiration of target cells from an impure background population, where we obtain purity levels of 90%–100% and demonstrate the enrichment of the target population with high-quality RNA extraction. A range of low cell numbers were aspirated using SASCA before undergoing whole transcriptome and genome analysis, exhibiting the ability to obtain endpoints from low-template inputs. Lastly, CTCs from patients with castration-resistant prostate cancer were isolated with this platform and the utility of this method was confirmed for rare-cell isolation. SASCA satisfies a need for an affordable option to isolate single cells or highly purified subpopulations of cells to probe complex mechanisms driving disease progression and resistance in patients with cancer.

scholarly journals Fixed single-cell RNA sequencing for understanding virus infection and host response

2020 ◽  
Author(s):  
Hoang Van Phan ◽  
Michiel van Gent ◽  
Nir Drayman ◽  
Anindita Basu ◽  
Michaela U. Gack ◽  
...  
Keyword(s):  
Single Cell ◽  
Rna Sequencing ◽  
High Throughput ◽  
Single Cells ◽  
Human Tumor ◽  
Tissue Cell ◽  
Pathogen Inactivation ◽  
Single Cell Rna Sequencing ◽  
Sequencing Studies ◽  
High Level

ABSTRACTSingle-cell RNA sequencing studies requiring intracellular protein staining, rare-cell sorting, or pathogen inactivation are severely limited because current high-throughput methods are incompatible with paraformaldehyde treatment, a very common and simple tissue/cell fixation and preservation technique. Here we present FD-seq, a high-throughput method for droplet-based RNA sequencing of paraformaldehyde-fixed, stained and sorted single-cells. We used FD-seq to address two important questions in virology. First, by analyzing a rare population of cells supporting lytic reactivation of the human tumor virus KSHV, we identified TMEM119 as a host factor that mediates reactivation. Second, we studied the transcriptome of lung cells infected with the coronavirus OC43, which causes the common cold and also serves as a safer model pathogen for SARS-CoV-2. We found that pro-inflammatory pathways are primarily upregulated in abortively-infected or uninfected bystander cells, which are exposed to the virus but fail to express high level of viral genes. FD-seq is suitable for characterizing rare cell populations of interest, for studying high-containment biological samples after inactivation, and for integrating intracellular phenotypic with transcriptomic information.

scholarly journals High content imaging for monitoring signalling dynamics in single cells

2020 ◽  
Vol 65 (4) ◽  
pp. R91-R100
Author(s):  
Kathryn L Garner
Keyword(s):  
Single Cell ◽  
Conformational Changes ◽  
Protein Interactions ◽  
Single Cells ◽  
Cellular Heterogeneity ◽  
Live Cells ◽  
Signalling Pathways ◽  
Protein Protein Interactions ◽  
High Content Imaging ◽  
Surface Receptors

All living cells are sensors of their environment: they sense signals, hormones, cytokines, and growth factors, among others. Binding of these signals to cell surface receptors initiates the transmission of messages along intracellular signalling pathways through protein–protein interactions, enzymatic modifications and conformational changes. Typically, the activation of signalling pathways are monitored in whole populations of cells, giving population average measures, often using experimental methods that destroy and homogenise the cell population. High content imaging is an automated, high-throughput fluorescence microscopy method that enables measurements of signal transduction pathways to be taken from live cells. It can be used to measure signalling dynamics, how the abundance of particular proteins of interest change over time, or to record how particular proteins move and change their localisation in response to a signal from their environment. Using this, and other single cell methods, it is becoming increasingly clear that cells are in fact very variable in their response to a given stimulus and in the quantities of cellular components they express, even in clonal (isogenic) cell lines. This review will discuss how high content imaging has contributed to our growing understanding of cellular heterogeneity. It will discuss how data generated has been combined with information theoretic approaches to quantify the amount of information transferred through noisy signalling pathways. Lastly, the relevance of heterogeneity to our understanding and treatment of disease will be considered, highlighting the importance of single cell measurements.

scholarly journals A carbon nanotube optical reporter maps endolysosomal lipid flux

2017 ◽  
Author(s):  
Prakrit V. Jena ◽  
Daniel Roxbury ◽  
Thomas V. Galassi ◽  
Leila Akkari ◽  
Christopher P. Horoszko ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Single Cell ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Live Cells ◽  
Lysosomal Storage ◽  
Drug Induced ◽  
Spatially Resolved ◽  
Order Of Magnitude ◽  
Multiple Drugs

ABSTRACTLipid accumulation within the lumen of endolysosomal vesicles is observed in various pathologies including atherosclerosis, liver disease, neurological disorders, lysosomal storage disorders, and cancer. Current methods cannot measure lipid flux specifically within the lysosomal lumen of live cells. We developed an optical reporter, composed of a photoluminescent carbon nanotube of a single chirality, which responds to lipid accumulation via modulation of the nanotube’s optical bandgap. The engineered nanomaterial, composed of short-single stranded DNA and a single nanotube chirality, localizes exclusively to the lumen of endolysosomal organelles without adversely affecting cell viability or proliferation, or organelle morphology, integrity, or function. The emission wavelength of the reporter can be spatially resolved from within the endolysosomal lumen to generate quantitative maps of lipid content in live cells. Endolysosomal lipid accumulation in cell lines, an example of drug-induced phospholipidosis (DIPL), was observed for multiple drugs in macrophages, and measurements of patient-derived Niemann-Pick type C fibroblasts identified lipid accumulation and phenotypic reversal of this lysosomal storage disease. Single-cell measurements using the reporter discerned sub-cellular differences in equilibrium lipid content, illuminating significant intracellular heterogeneity among endolysosomal organelles of differentiating bone marrow-derived monocytes. Single-cell kinetics of lipoprotein-derived cholesterol accumulation within macrophages revealed rates that differed among cells by an order of magnitude. This carbon nanotube optical reporter of endolysosomal lipid content in live cells confers new capabilities for drug development processes and the investigation of lipid-linked diseases.

In-Situ Dual Beam (FIBSEM) Techniques for Probe Pad Deposition and Dielectric Integrity Inspection in 0.2 μm Technology DRAM Single Cells

1999 ◽  
Author(s):  
Gunnar Zimmermann ◽  
Richard Chapman
Keyword(s):  
Electron Beam ◽  
Single Cell ◽  
Single Cells ◽  
Ion Beam ◽  
Gate Oxide ◽  
Ion Milling ◽  
Dual Beam ◽  
Sem Imaging ◽  
Innovative Techniques

Abstract Dual beam FIBSEM systems invite the use of innovative techniques to localize IC fails both electrically and physically. For electrical localization, we present a quick and reliable in-situ FIBSEM technique to deposit probe pads with very low parasitic leakage (Ipara < 4E-11A at 3V). The probe pads were Pt, deposited with ion beam assistance, on top of highly insulating SiOx, deposited with electron beam assistance. The buried plate (n-Band), p-well, wordline and bitline of a failing and a good 0.2 μm technology DRAM single cell were contacted. Both cells shared the same wordline for direct comparison of cell characteristics. Through this technique we electrically isolated the fail to a single cell by detecting leakage between the polysilicon wordline gate and the cell diffusion. For physical localization, we present a completely in-situ FIBSEM technique that combines ion milling, XeF2 staining and SEM imaging. With this technique, the electrically isolated fail was found to be a hole in the gate oxide at the bad cell.

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