scholarly journals Improving oligo-conjugated antibody signal in multimodal single-cell analysis

2020 ◽  
Author(s):  
Terkild Brink Buus ◽  
Alberto Herrera ◽  
Ellie Ivanova ◽  
Eleni Mimitou ◽  
Anthony Cheng ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Cell Number ◽  
Surface Proteins ◽  
Biological Information ◽  
Antibody Concentration ◽  
Mass Cytometry ◽  
Background Signal ◽  
High Background

AbstractSimultaneous measurement of surface proteins and gene expression within single cells offers high resolution snapshots of complex cell populations. These methods rely on staining cells with oligo-conjugated antibodies analogous to staining for flow- and mass cytometry. Unlike flow- and mass cytometry, signal from oligo-conjugated antibodies is not hampered by spectral overlap or limited by the number of metal isotopes, making it a highly sensitive and scalable approach. Signal from oligo-conjugated antibodies is quantified by counting reads from high-throughput sequencing. Consequently, cost of sequencing is strictly dependent on the signal intensities and background from the pool of antibodies used in analysis. Thus, considering the “cost-of-signal” as well as optimizing “signal-to-noise”, makes titration of oligo-conjugated antibody panels more complex and even more important than for flow- and mass cytometry. In this study, we investigated the titration response of a panel of oligo-conjugated antibodies towards four variables: Antibody concentration, staining volume, cell number at staining, and tissue of origin. We find that staining with high antibody concentrations recommended by published protocols and commercial vendors cause unnecessarily high background signal and that concentrations of many antibodies can be drastically reduced without loss of biological information. Reducing staining volume only affects antibodies targeting highly abundant epitopes used at low concentrations and can be counteracted by reducing cell numbers at staining. We find that background signal from empty droplets can account for a major fraction of the total sequencing reads and is primarily derived from antibodies used at high concentrations. Together, this study provides new insight into the titration response and background signal of oligo-conjugated antibodies and offers concrete guidelines on how such panels can be improved.

scholarly journals Improving oligo-conjugated antibody signal in multimodal single-cell analysis

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Terkild B Buus ◽  
Alberto Herrera ◽  
Ellie Ivanova ◽  
Eleni Mimitou ◽  
Anthony Cheng ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Cell Number ◽  
Surface Proteins ◽  
Biological Information ◽  
High Background ◽  
Low Concentrations ◽  
High Concentrations ◽  
Insight Into

Simultaneous measurement of surface proteins and gene expression within single cells using oligo-conjugated antibodies offers high-resolution snapshots of complex cell populations. Signal from oligo-conjugated antibodies is quantified by high-throughput sequencing and is highly scalable and sensitive. We investigated the response of oligo-conjugated antibodies towards four variables: concentration, staining volume, cell number at staining, and tissue. We find that staining with recommended antibody concentrations causes unnecessarily high background and amount of antibody used can be drastically reduced without loss of biological information. Reducing staining volume only affects antibodies targeting abundant epitopes used at low concentrations and is counteracted by reducing cell numbers. Adjusting concentrations increases signal, lowers background, and reduces costs. Background signal can account for a major fraction of total sequencing and is primarily derived from antibodies used at high concentrations. This study provides new insight into titration response and background of oligo-conjugated antibodies and offers concrete guidelines to improve such panels.

High-Throughput Production of Single-Cell Microparticles Using an Inkjet Printing Technology

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Tao Xu ◽  
Helen Kincaid ◽  
Anthony Atala ◽  
James J. Yoo
Keyword(s):  
Single Cell ◽  
High Throughput ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Stem Cell Differentiation ◽  
Cell Number ◽  
High Throughput Drug Screening ◽  
Alginate Concentration ◽  
High Throughput Method ◽  
Normal Cellular Function

In this study, a novel biocompatible and inexpensive method for the rapid production of single-cell based microparticles is described. Using an HP DeskJet 550C printer, alginate microparticles containing one to several insulin-producing cells (beta-TC6) were fabricated by coprinting the cells and sodium alginate suspension into a CaCl2 solution. This method is able to generate microparticles of 30–60μm in diameter at a rate as high as 55,000particles∕s. Cell survival assays showed that more than 89% of printed cells survived the fabrication process. The printed beta-TC6 cells demonstrated continuous insulin secretion over a 6day period, which suggests that the printed cells are able to maintain normal cellular function within the microparticles. We show that the printing conditions, such as cell number, alginate concentration, and ionic strengths of CaCl2, influence cellular distribution and geometry of the printed particles. This study presents a simple and high-throughput method to encapsulate single cells, and this technique may be applied in various research investigations, including single-cell analysis, high-throughput drug screening, and stem cell differentiation at the single-cell level.

scholarly journals Strongly enhanced bacterial bioluminescence with the ilux operon for single-cell imaging

2018 ◽  
Vol 115 (5) ◽  
pp. 962-967 ◽  
Author(s):  
Carola Gregor ◽  
Klaus C. Gwosch ◽  
Steffen J. Sahl ◽  
Stefan W. Hell
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Flavin Mononucleotide ◽  
Background Signal ◽  
Cell Level ◽  
Spatiotemporal Resolution ◽  
High Background ◽  
E Coli ◽  
Bacterial Bioluminescence ◽  
Single Cell Imaging

Bioluminescence imaging of single cells is often complicated by the requirement of exogenous luciferins that can be poorly cell-permeable or produce high background signal. Bacterial bioluminescence is unique in that it uses reduced flavin mononucleotide as a luciferin, which is abundant in all cells, making this system purely genetically encodable by the lux operon. Unfortunately, the use of bacterial bioluminescence has been limited by its low brightness compared with other luciferases. Here, we report the generation of an improved lux operon named ilux with an approximately sevenfold increased brightness when expressed in Escherichia coli; ilux can be used to image single E. coli cells with enhanced spatiotemporal resolution over several days. In addition, since only metabolically active cells produce bioluminescent signal, we show that ilux can be used to observe the effect of different antibiotics on cell viability on the single-cell level.

scholarly journals TUP1, CPH1 and EFG1 Make Independent Contributions to Filamentation in Candida albicans

Genetics ◽  
2000 ◽  
Vol 155 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Burkhard R Braun ◽  
Alexander D Johnson
Keyword(s):  
Candida Albicans ◽  
Environmental Conditions ◽  
Target Genes ◽  
Single Cells ◽  
Filamentous Growth ◽  
Surface Proteins ◽  
Pathway Expression ◽  
Separate Pathway ◽  
The Common ◽  
Growth Pathway

Abstract The common fungal pathogen, Candida albicans, can grow either as single cells or as filaments (hyphae), depending on environmental conditions. Several transcriptional regulators have been identified as having key roles in controlling filamentous growth, including the products of the TUP1, CPH1, and EFG1 genes. We show, through a set of single, double, and triple mutants, that these genes act in an additive fashion to control filamentous growth, suggesting that each gene represents a separate pathway of control. We also show that environmentally induced filamentous growth can occur even in the absence of all three of these genes, providing evidence for a fourth regulatory pathway. Expression of a collection of structural genes associated with filamentous growth, including HYR1, ECE1, HWP1, ALS1, and CHS2, was monitored in strains lacking each combination of TUP1, EFG1, and CPH1. Different patterns of expression were observed among these target genes, supporting the hypothesis that these three regulatory proteins engage in a network of individual connections to downstream genes and arguing against a model whereby the target genes are regulated through a central filamentous growth pathway. The results suggest the existence of several distinct types of filamentous forms of C. albicans, each dependent on a particular set of environmental conditions and each expressing a unique set of surface proteins.

scholarly journals Aptamer BC 007’s Affinity to Specific and Less-Specific Anti-SARS-CoV-2 Neutralizing Antibodies

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 932
Author(s):  
Annekathrin Haberland ◽  
Oxana Krylova ◽  
Heike Nikolenko ◽  
Peter Göttel ◽  
Andre Dallmann ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Resonance Spectroscopy ◽  
Plastic Plate ◽  
Calorimetric Titration ◽  
Background Signal ◽  
High Background ◽  
Specific Virus ◽  
Binding Sequence

COVID-19 is a pandemic respiratory disease that is caused by the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Anti-SARS-CoV-2 antibodies are essential weapons that a patient with COVID-19 has to combat the disease. When now repurposing a drug, namely an aptamer that interacts with SARS-CoV-2 proteins for COVID-19 treatment (BC 007), which is, however, a neutralizer of pathogenic autoantibodies in its original indication, the possibility of also binding and neutralizing anti-SARS-CoV-2 antibodies must be considered. Here, the highly specific virus-neutralizing antibodies have to be distinguished from the ones that also show cross-reactivity to tissues. The last-mentioned could be the origin of the widely reported SARS-CoV-2-induced autoimmunity, which should also become a target of therapy. We, therefore, used enzyme-linked immunosorbent assay (ELISA) technology to assess the binding of well-characterized publicly accessible anti-SARS-CoV-2 antibodies (CV07-209 and CV07-270) with BC 007. Nuclear magnetic resonance spectroscopy, isothermal calorimetric titration, and circular dichroism spectroscopy were additionally used to test the binding of BC 007 to DNA-binding sequence segments of these antibodies. BC 007 did not bind to the highly specific neutralizing anti-SARS-CoV-2 antibody but did bind to the less specific one. This, however, was a lot less compared to an autoantibody of its original indication (14.2%, range 11.0–21.5%). It was also interesting to see that the less-specific anti-SARS-CoV-2 antibody also showed a high background signal in the ELISA (binding on NeutrAvidin-coated or activated but noncoated plastic plate). These initial experiments suggest that the risk of binding and neutralizing highly specific anti-SARS CoV-2 antibodies by BC 007 should be low.

scholarly journals Microfluidic platform accelerates tissue processing into single cells for molecular analysis and primary culture models

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jeremy A. Lombardo ◽  
Marzieh Aliaghaei ◽  
Quy H. Nguyen ◽  
Kai Kessenbrock ◽  
Jered B. Haun
Keyword(s):  
Single Cell ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Cell Analysis ◽  
Processing Technologies ◽  
Microfluidic Platform ◽  
Tissue Processing ◽  
Single Cell Rna Sequencing ◽  
Culture Models ◽  
Tissue Digestion

AbstractTissues are complex mixtures of different cell subtypes, and this diversity is increasingly characterized using high-throughput single cell analysis methods. However, these efforts are hindered, as tissues must first be dissociated into single cell suspensions using methods that are often inefficient, labor-intensive, highly variable, and potentially biased towards certain cell subtypes. Here, we present a microfluidic platform consisting of three tissue processing technologies that combine tissue digestion, disaggregation, and filtration. The platform is evaluated using a diverse array of tissues. For kidney and mammary tumor, microfluidic processing produces 2.5-fold more single cells. Single cell RNA sequencing further reveals that endothelial cells, fibroblasts, and basal epithelium are enriched without affecting stress response. For liver and heart, processing time is dramatically reduced. We also demonstrate that recovery of cells from the system at periodic intervals during processing increases hepatocyte and cardiomyocyte numbers, as well as increases reproducibility from batch-to-batch for all tissues.

scholarly journals Multiplexed profiling of single-cell extracellular vesicles secretion

2019 ◽  
Vol 116 (13) ◽  
pp. 5979-5984 ◽  
Author(s):  
Yahui Ji ◽  
Dongyuan Qi ◽  
Linmei Li ◽  
Haoran Su ◽  
Xiaojie Li ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Lines ◽  
Extracellular Vesicles ◽  
Single Cell Analysis ◽  
Comprehensive Evaluation ◽  
Single Cells ◽  
Deep Understanding ◽  
Principal Component ◽  
Cell Heterogeneity ◽  
Indispensable Tool

Extracellular vesicles (EVs) are important intercellular mediators regulating health and diseases. Conventional methods for EV surface marker profiling, which was based on population measurements, masked the cell-to-cell heterogeneity in the quantity and phenotypes of EV secretion. Herein, by using spatially patterned antibody barcodes, we realized multiplexed profiling of single-cell EV secretion from more than 1,000 single cells simultaneously. Applying this platform to profile human oral squamous cell carcinoma (OSCC) cell lines led to a deep understanding of previously undifferentiated single-cell heterogeneity underlying EV secretion. Notably, we observed that the decrement of certain EV phenotypes (e.g.,CD63+EV) was associated with the invasive feature of both OSCC cell lines and primary OSCC cells. We also realized multiplexed detection of EV secretion and cytokines secretion simultaneously from the same single cells to investigate the multidimensional spectrum of cellular communications, from which we resolved tiered functional subgroups with distinct secretion profiles by visualized clustering and principal component analysis. In particular, we found that different cell subgroups dominated EV secretion and cytokine secretion. The technology introduced here enables a comprehensive evaluation of EV secretion heterogeneity at single-cell level, which may become an indispensable tool to complement current single-cell analysis and EV research.

scholarly journals Direct observation of frequency modulated transcription in single cells using light activation

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Daniel R Larson ◽  
Christoph Fritzsch ◽  
Liang Sun ◽  
Xiuhau Meng ◽  
David S Lawrence ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Molecule ◽  
Single Cell Analysis ◽  
Cell Model ◽  
Single Cells ◽  
Single Gene ◽  
Gene Activation ◽  
Light Activation ◽  
Dynamic Synthesis ◽  
Single Cell Model

Single-cell analysis has revealed that transcription is dynamic and stochastic, but tools are lacking that can determine the mechanism operating at a single gene. Here we utilize single-molecule observations of RNA in fixed and living cells to develop a single-cell model of steroid-receptor mediated gene activation. We determine that steroids drive mRNA synthesis by frequency modulation of transcription. This digital behavior in single cells gives rise to the well-known analog dose response across the population. To test this model, we developed a light-activation technology to turn on a single steroid-responsive gene and follow dynamic synthesis of RNA from the activated locus.

scholarly journals The Development of Single-Cell Metabolism and Its Role in Studying Cancer Emergent Properties

2022 ◽  
Vol 11 ◽  
Author(s):  
Dingju Wei ◽  
Meng Xu ◽  
Zhihua Wang ◽  
Jingjing Tong
Keyword(s):  
Tumor Cell ◽  
Single Cell ◽  
Immune Escape ◽  
Cell Metabolism ◽  
Single Cells ◽  
Metabolic Reprogramming ◽  
Biological Information ◽  
Emergent Properties ◽  
Anti Cancer ◽  
Cell Metabolomics

Metabolic reprogramming is one of the hallmarks of malignant tumors, which provides energy and material basis for tumor rapid proliferation, immune escape, as well as extensive invasion and metastasis. Blocking the energy and material supply of tumor cells is one of the strategies to treat tumor, however tumor cell metabolic heterogeneity prevents metabolic-based anti-cancer treatment. Therefore, searching for the key metabolic factors that regulate cell cancerous change and tumor recurrence has become a major challenge. Emerging technology––single-cell metabolomics is different from the traditional metabolomics that obtains average information of a group of cells. Single-cell metabolomics identifies the metabolites of single cells in different states by mass spectrometry, and captures the molecular biological information of the energy and substances synthesized in single cells, which provides more detailed information for tumor treatment metabolic target screening. This review will combine the current research status of tumor cell metabolism with the advantages of single-cell metabolomics technology, and explore the role of single-cell sequencing technology in searching key factors regulating tumor metabolism. The addition of single-cell technology will accelerate the development of metabolism-based anti-cancer strategies, which may greatly improve the prognostic survival rate of cancer patients.

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