single-cell detection
Dotaz
Zobrazit nápovědu
... Noninvasive metabolic assessment of single cells / David K. ... ... Gardner -- Laser capture microdissection for analysis of single cells / Nobuki Nakamura ... ... ... from single cells / Kenneth E. ... ... Wangh -- Efficient isothermal amplification of the entire genome from single cells / Karen V. ... ... and detection of aneuploidy in single cells using DNA array-based comparative genomic hybridization ...
Methods in molecular medicine, ISSN 1543-1894 132
xi, 182 s. : il., tab.
Analysing the chemical content of individual cells has already been proven to reveal unique information on various biological processes. Single-cell analysis provides more accurate and reliable results for biology and medicine than analyses of extracts from cell populations, where a natural heterogeneity is averaged. To meet the requirements in the research of important biologically active molecules, such as caspases, we have developed a miniaturized device for simultaneous analyses of individual cells. A stainless steel body with a carousel holder enables high-sensitivity parallel detections in eight microvials. The holder is mounted in front of a photomultiplier tube with cooled photocathode working in photon counting mode. The detection of active caspase-3/7, central effector caspases in apoptosis, in single cells is based on the bioluminescence chemistry commercially available as Caspase-Glo®3/7 reagent developed by Promega. Individual cells were captured from a culture medium under microscope and transferred by micromanipulator into detection microvial filled with the reagent. As a result of testing, the limits of detection and quantification were determined to be 0.27/0.86 of active caspase-3/7 content in an average apoptotic cell and 0.46/2.92 for non-apoptotic cells. Application potential of this technology in laboratory diagnostics and related medical research is discussed. Graphical abstract Miniaturized device for simultaneous analyses of individual cells.
- MeSH
- analýza jednotlivých buněk přístrojové vybavení metody MeSH
- apoptóza * MeSH
- design vybavení MeSH
- enzymatické testy přístrojové vybavení metody MeSH
- kaspasa 3 analýza metabolismus MeSH
- kaspasa 7 analýza metabolismus MeSH
- kultivované buňky MeSH
- luminiscenční měření přístrojové vybavení metody MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Caspases are key enzymes activated during the apoptotic machinery. Apoptosis as a way of programmed cell death becomes deregulated in some pathologies including cancer transformations, neurodegenerative, or autoimmune diseases. Most of the methods available for the detection of apoptosis and caspases provide qualitative information only or quantification data as an average from cell populations or cell lysates. Several reports point to the importance of more accurate single-cell analyses in biomedical studies due to heterogeneity at tissue as well as cell level. To meet these requirements, we developed a miniaturized device enabling detection and quantification of active caspase-3/7 in individual cells at a femtogram level (10(-15) g). The active caspase-3/7 detection protocol is based on the bioluminescence chemistry commercially available as a Caspase-Glo™ 3/7 reagent developed by Promega. As a model, we used human stem cells treated by camptothecin to induce apoptosis. Individual apoptotic cells were captured from a culture medium under a microscope and transferred by a micromanipulation system into a detection capillary containing 2 μl of the reagent. Cells without activation by camptothecin served as negative controls. The detection limit of active caspase-3/7 achieved in the miniaturized system was determined as 0.20 and limit of quantification as 0.65 of the amount found in a single apoptotic human stem cell. Such a sensitive method could have a wide application potential in laboratory medicine and related clinically oriented research.
- MeSH
- analýza jednotlivých buněk přístrojové vybavení MeSH
- apoptóza * MeSH
- buněčná diferenciace MeSH
- crista neuralis cytologie MeSH
- design vybavení MeSH
- kamptothecin chemie MeSH
- kaspasa 3 metabolismus MeSH
- kaspasa 7 metabolismus MeSH
- kmenové buňky účinky léků patologie MeSH
- lidé MeSH
- luminiscence MeSH
- mikromanipulace MeSH
- miniaturizace přístrojové vybavení MeSH
- reprodukovatelnost výsledků MeSH
- zánět MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This overview deals with the latest development of electrophoresis in capillaries and microfluidic devices coupled to MS detection. A wide selection of relevant articles covers the literature published from January 2010 till June 2012 as a continuation of the review article on the same topic by Pantuckova et al. [Electrophoresis 2011, 32, 43-51]. Special attention is paid to the new improvements in instrumentation and methodology of three interfacing methods, ESI, matrix-assisted desorption/ionization, and ICP. Representative examples illustrate applications in the proteomics, glycomics, metabolomics, biomarker research, forensics, pharmacology, food analysis and single-cell analysis. The combinations of MS with capillary versions of electrochromatography, ITP, IEF, and micellar electrokinetic chromatography are not included.
- MeSH
- analýza jednotlivých buněk metody MeSH
- analýza potravin metody MeSH
- biologické markery analýza MeSH
- elektroforéza kapilární metody trendy MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací metody MeSH
- hmotnostní spektrometrie metody MeSH
- kontaminace léku MeSH
- mikrofluidní analytické techniky přístrojové vybavení MeSH
- proteomika metody MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Correct determination of the instantaneous level and changes of relevant proteins inside individual cells is essential for correct interpretation and understanding of physiological, diagnostic, and therapeutic events. Thus, single-cell analyses are important for quantification of natural cellular heterogeneity, which cannot be evaluated from averaged data of a cell population measurements. Here, we developed an original highly sensitive and selective instrumentation and methodology based on homogeneous single-step bioluminescence assay to quantify caspases and evaluate their heterogeneity in individual cells. Individual suspended cells are selected under microscope and reliably transferred into the 7 μl detection vials by a micromanipulator. The sensitivity of the method is given by implementation of photomultiplying tube with a cooled photocathode working in the photon counting mode. By optimization of our device and methodology, the limits of detection and quantitation were decreased down to 2.1 and 7.0 fg of recombinant caspase-3, respectively. These masses are lower than average amounts of caspase-3/7 in individual apoptotic and even non-apoptotic cells. As a proof of concept, the content of caspase-3/7 in single treated and untreated HeLa cells was determined to be 154 and 25 fg, respectively. Based on these results, we aim to use the technology for investigations of non-apoptotic functions of caspases.
- MeSH
- apoptóza * MeSH
- HeLa buňky MeSH
- kaspasa 3 MeSH
- kaspasy * MeSH
- lidé MeSH
- technologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
DNA double stranded breaks (DSBs) are the most serious type of lesions introduced into chromatin by ionizing radiation. During DSB repair, cells recruit different proteins to the damaged sites in a manner dependent on local chromatin structure, DSB location in the nucleus, and the repair pathway entered. 53BP1 is one of the important players participating in repair pathway decision of the cell. Although many molecular biology details have been investigated, the architecture of 53BP1 repair foci and its development during the post-irradiation time, especially the period of protein recruitment, remains to be elucidated. Super-resolution light microscopy is a powerful new tool to approach such studies in 3D-conserved cell nuclei. Recently, we demonstrated the applicability of single molecule localization microscopy (SMLM) as one of these highly resolving methods for analyses of dynamic repair protein distribution and repair focus internal nano-architecture in intact cell nuclei. In the present study, we focused our investigation on 53BP1 foci in differently radio-resistant cell types, moderately radio-resistant neonatal human dermal fibroblasts (NHDF) and highly radio-resistant U87 glioblastoma cells, exposed to high-LET 15N-ion radiation. At given time points up to 24 h post irradiation with doses of 1.3 Gy and 4.0 Gy, the coordinates and spatial distribution of fluorescently tagged 53BP1 molecules was quantitatively evaluated at the resolution of 10⁻20 nm. Clusters of these tags were determined as sub-units of repair foci according to SMLM parameters. The formation and relaxation of such clusters was studied. The higher dose generated sufficient numbers of DNA breaks to compare the post-irradiation dynamics of 53BP1 during DSB processing for the cell types studied. A perpendicular (90°) irradiation scheme was used with the 4.0 Gy dose to achieve better separation of a relatively high number of particle tracks typically crossing each nucleus. For analyses along ion-tracks, the dose was reduced to 1.3 Gy and applied in combination with a sharp angle irradiation (10° relative to the cell plane). The results reveal a higher ratio of 53BP1 proteins recruited into SMLM defined clusters in fibroblasts as compared to U87 cells. Moreover, the speed of foci and thus cluster formation and relaxation also differed for the cell types. In both NHDF and U87 cells, a certain number of the detected and functionally relevant clusters remained persistent even 24 h post irradiation; however, the number of these clusters again varied for the cell types. Altogether, our findings indicate that repair cluster formation as determined by SMLM and the relaxation (i.e., the remaining 53BP1 tags no longer fulfill the cluster definition) is cell type dependent and may be functionally explained and correlated to cell specific radio-sensitivity. The present study demonstrates that SMLM is a highly appropriate method for investigations of spatiotemporal protein organization in cell nuclei and how it influences the cell decision for a particular repair pathway at a given DSB site.
This review provides a brief information on principles and possible applications of the comet assay method, known as single cell gel electrophoresis, allowing to analyze DNA damage. This method developed in the mid-seventies was widely used in the early eighties of the last century. Several modifications of the comet assay approach made this method an attractive tool in various fields such as molecular biology research, quality control, clinical diagnosis, and monitoring of environmental pollution.
Hypervariable T cell receptors (TCRs) play a key role in adaptive immunity, recognizing a vast diversity of pathogen-derived antigens. Our ability to extract clinically relevant information from large high-throughput sequencing of TCR repertoires (RepSeq) data is limited, because little is known about TCR-disease associations. We present Antigen-specific Lymphocyte Identification by Clustering of Expanded sequences (ALICE), a statistical approach that identifies TCR sequences actively involved in current immune responses from a single RepSeq sample and apply it to repertoires of patients with a variety of disorders - patients with autoimmune disease (ankylosing spondylitis [AS]), under cancer immunotherapy, or subject to an acute infection (live yellow fever [YF] vaccine). We validate the method with independent assays. ALICE requires no longitudinal data collection nor large cohorts, and it is directly applicable to most RepSeq datasets. Its results facilitate the identification of TCR variants associated with diseases and conditions, which can be used for diagnostics and rational vaccine design.
- MeSH
- adaptivní imunita genetika MeSH
- antigeny virové MeSH
- antigeny MeSH
- hypervariabilní oblasti genetika fyziologie MeSH
- imunoterapie MeSH
- lidé MeSH
- receptory antigenů T-buněk imunologie metabolismus fyziologie MeSH
- sekvenční analýza DNA metody MeSH
- shluková analýza MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Circulating tumor cells (CTCs) are rare cells that can be found in the peripheral blood of cancer patients. They have been demonstrated to be useful prognostic markers in many cancer types. Within the last decade various methods have been developed to detect rare cells within a liquid biopsy from a cancer patient. These methods have revealed the phenotypic diversity of CTCs and how they can represent the complement of cells that are found in a tumor. Single-cell proteogenomics has emerged as an all-encompassing next-generation technological approach for CTC research. This allows for the deconstruction of cellular heterogeneity, dynamics of metastatic initiation and progression, and response or resistance to therapeutics in the clinical settings. We take advantage of this opportunity to investigate CTC heterogeneity and understand their full potential in precision medicine.The high-definition single-cell analysis (HD-SCA) workflow combines detection of the entire population of CTCs and rare cancer related cells with single-cell genomic analysis and may therefore provide insight into their subpopulations based on molecular as well as morphological data. In this chapter we describe in detail the protocols from isolation of a candidate cell from a microscopy slide, through whole-genome amplification and library preparation, to CNV analysis of identified cells from the HD-SCA workflow. This process may also be applicable to any platform starting with a standard microscopy slide or isolated cell of interest.
