scholarly journals Measurement of cytoplasmic fluorescence depolarization of single cells in a flow system.

1977 ◽  
Vol 25 (7) ◽  
pp. 597-600 ◽  
Author(s):  
G B Price ◽  
M J McCutcheon ◽  
W B Taylor ◽  
R G Miller
Keyword(s):  
Light Source ◽  
Flow System ◽  
Single Cells ◽  
Polarized Light ◽  
The State ◽  
Fluorescence Depolarization ◽  
Fluorescent Signal ◽  
Viable Cells ◽  
A Cell ◽  
Signal Changes

We have built a flow system in which we can analyze and sort individual viable cells on the basis of their cytoplasmic microviscosity. The average cytoplasmic microviscosity (or cytoplasmic structuredness) of a cell can be quantitated by exciting fluorescein molecules in the cytoplasm of the cell with a polarized light source and measuring the extent of depolarization of the fluorescent signal. Changes in the state of a cell (e.g., the reception of a signal inducing the cell to differentiate) often appear to be associated with changes in cytoplasmic microviscosity, these changes being detectable within hours of the inducing signal. An example of one such change is presented.

scholarly journals Denaturation and condensation of intracellular nucleic acids monitored by fluorescence depolarization of intercalating dyes in individual cells.

1989 ◽  
Vol 37 (11) ◽  
pp. 1699-1704 ◽  
Author(s):  
W Beisker ◽  
W G Eisert
Keyword(s):  
Nucleic Acids ◽  
Conformational Changes ◽  
Single Cells ◽  
Polarized Light ◽  
Fluorescence Emission ◽  
Polarization Measurement ◽  
Dye Molecules ◽  
Fluorescence Depolarization ◽  
Double Beam ◽  
Cellular Dna

The intercalating binding of planar aromatic dye molecules to nucleic acids can be analyzed using fluorescence depolarization measurements of the dye molecules excited by linearly polarized light. In this study, we investigated the conformational changes of the intracellular DNA-dye complex in single cells. Flow cytometry, combined with a newly developed double-beam autocompensation technique, permitted rapid high-precision fluorescence depolarization measurements on a large number of individual cells. The dyes ethidium bromide (EB), propidium iodide (PI), and acridine orange (AO) were used in this study. Depending on the dye-to-phosphate ratio of the nuclear acid-dye complex, as well as on the spatial dye structure itself, internal and external binding sites can be monitored by fluorescence depolarization analysis. Both energy transfer and rotation and vibration of the dye molecules cause depolarization of the fluorescence emission. Differences in the concentration-dependent dye fluorescence depolarization values between PI and EB on one side and AO on the other side can be interpreted as a denaturation and condensation of double-stranded DNA regions by AO. We further show that the fluorescence polarization measurement technique can be used in an alternative way to monitor thermal denaturation of cellular DNA.

scholarly journals Leukocytes with chromosome Y loss have reduced abundance of the cell surface immunoprotein CD99

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Mattisson ◽  
Marcus Danielsson ◽  
Maria Hammond ◽  
Hanna Davies ◽  
Caroline J. Gallant ◽  
...  
Keyword(s):  
Cell Surface ◽  
Single Cells ◽  
Surface Protein ◽  
Protein Abundance ◽  
Blood Leukocytes ◽  
Chromosome Y ◽  
Increased Risk ◽  
A Cell ◽  
Pseudoautosomal Regions ◽  
Male Specific

AbstractMosaic loss of chromosome Y (LOY) in immune cells is a male-specific mutation associated with increased risk for morbidity and mortality. The CD99 gene, positioned in the pseudoautosomal regions of chromosomes X and Y, encodes a cell surface protein essential for several key properties of leukocytes and immune system functions. Here we used CITE-seq for simultaneous quantification of CD99 derived mRNA and cell surface CD99 protein abundance in relation to LOY in single cells. The abundance of CD99 molecules was lower on the surfaces of LOY cells compared with cells without this aneuploidy in all six types of leukocytes studied, while the abundance of CD proteins encoded by genes located on autosomal chromosomes were independent from LOY. These results connect LOY in single cells with immune related cellular properties at the protein level, providing mechanistic insight regarding disease vulnerability in men affected with mosaic chromosome Y loss in blood leukocytes.

Development of a cell delivery system using alginate microbeads for tissue regeneration

2016 ◽  
Vol 4 (20) ◽  
pp. 3515-3525 ◽  
Author(s):  
Shirae K. Leslie ◽  
Anthony M. Nicolini ◽  
Gobalakrishnan Sundaresan ◽  
Jamal Zweit ◽  
Barbara D. Boyan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Delivery System ◽  
Tissue Regeneration ◽  
Cell Delivery ◽  
Adipose Derived Stem Cells ◽  
Viable Cells ◽  
A Cell

Alginate microbeads incorporating adipose-derived stem cells (ASCs) have potential for delivering viable cells capable of facilitating tissue regeneration.

scholarly journals IV. On double refraction in a viscous fluid in motion

1874 ◽  
Vol 22 (148-155) ◽  
pp. 46-47 ◽  
Keyword(s):  
Internal Friction ◽  
Viscous Fluid ◽  
Polarized Light ◽  
Elastic Solid ◽  
The State ◽  
Solid Cylinder ◽  
Annular Space ◽  
Double Refraction ◽  
Fresh Start ◽  
The Moment

According to Poisson’s theory of the internal friction of fluids, a viscous fluid behaves as an elastic solid would do if it were periodically liquefied for an instant and solidified again, so that at each fresh start it becomes for the moment like an elastic solid free from strain. The state of strain of certain transparent bodies may be investigated by means of their action on polarized light. This action was observed by Brewster, and was shown by Fresnel to be an instance of double refraction. In 1866 I made some attempts to ascertain whether the state of strain in a viscous fluid in motion could be detected by its action on polarized light. I had a cylindrical box with a glass bottom. Within this box a solid cylinder could be made to rotate. The fluid to be examined was placed in the annular space between this cylinder and the sides of the box. Polarized light was thrown up through the fluid parallel to the axis, and the inner cylinder was then made to rotate. I was unable to obtain any result with solution of gum or sirup of sugar, though I observed an effect on polarized light when I compressed some Canada balsam which had become very thick and almost solid in a bottle.

The 1992 Polarized Light Source

2002 ◽  
Author(s):  
R. Alley ◽  
M. Woods ◽  
M. Browne ◽  
J. Frisch ◽  
M. Zolotorev
Keyword(s):  
Light Source ◽  
Polarized Light

scholarly journals The use of a slide spinner in the analysis of cell dispersion.

1976 ◽  
Vol 24 (1) ◽  
pp. 11-15 ◽  
Author(s):  
R C Wolley ◽  
H M Dembitzer ◽  
F Herz ◽  
K Schreiber ◽  
L G Koss
Keyword(s):  
Cell Suspension ◽  
Single Cells ◽  
Cell Loss ◽  
Optimum Conditions ◽  
Isolated Cells ◽  
Cell Dispersion ◽  
Cervical Cancer Cells ◽  
A Cell ◽  
Human Cervical Cancer Cells ◽  
Human Cervical Cancer

A simple and reliable method of determining the degree of dispersion of a cell suspension has been developed using the Perkin-Elmer Uni-Smear Spinner. Optimum conditions regarding rate and duration of spin, etc., were first ascertained using dispersed cell cultures including human cervical cancer cells as well as gynecologic samples. After spinning, single cells in suspension appeared as isolated cells on the slides. Cell aggregates, on the other hand, remained together. Therefore, the distribution of cells in various sized aggregates could be easily quantitated and the slides retained for future review. This method was used to evaluate the dispersing effects of trypsin, ethylenediaminetetraacetate and and syringing human on human gynecology samples obtained by routine cervical scrapes. None of the dispersion methods has, so far, produced an adequate monodispersed cell suspension without unacceptable cell loss.

Microphotometry of Underwater Shadowing by a Moss from a Niagara Escarpment Waterfall

2010 ◽  
Vol 17 (1) ◽  
pp. 125-131
Author(s):  
Howard J. Swatland
Keyword(s):  
Point Source ◽  
Single Cells ◽  
Incident Light ◽  
Polarized Light ◽  
Specular Reflectance ◽  
Light Spectra ◽  
Niagara Escarpment ◽  
Single Leaf ◽  
Diffuse Illumination ◽  
Air Water Interface

AbstractMicroscope and fiber-optic spectrophotometry of transmittance and backscattering both showed moss leaves to be capable of casting strong shadows, with a single leaf blocking approximately 90% of incident light from a point source. In leaves with only one layer of cells, the transmittance through the cytoplasm of single cells was similar to that for whole leaves. Analysis of cell wall birefringence by polarized-light interferometry indicated that cell walls might normally scatter rather than transmit light. Spectra transmitted through, or backscattered from, the upper green layers of moss were dominated by selective absorbance from chlorophyll, but there was also evidence of wavelength-dependent scattering, as detected in the lower layers of brown, dead moss. Specular reflectance from moss leaves was detected by polarimetry and may have contributed to the relatively high macroscopic transmittance of stationary moss in water. Shadowing by moss leaves was confirmed by dynamic measurements of mosses in turbulent water without bubbles. Flicker patterns from leaves were superimposed on the underwater flicker pattern created at the air-water interface, thus flecks of light were reduced in intensity, increased in frequency, and decreased in duration. This was detected with both point source and diffuse illumination of samples.

scholarly journals Localized mechanical stimulation of single cells with engineered spatio-temporal profile

Lab on a Chip ◽  
2018 ◽  
Vol 18 (19) ◽  
pp. 2955-2965 ◽  
Author(s):  
M. Monticelli ◽  
D. S. Jokhun ◽  
D. Petti ◽  
G. V. Shivashankar ◽  
R. Bertacco
Keyword(s):  
Cell Culture ◽  
Mechanical Stimulation ◽  
Single Cells ◽  
Mechanical Stimuli ◽  
Temporal Profile ◽  
A Cell ◽  
Spatio Temporal ◽  
Stimulation Of

We introduce a new platform for mechanobiology based on active substrates, made of Fe-coated polymeric micropillars, capable to apply mechanical stimuli with tunable spatio-temporal profile on a cell culture.

Growth in cell length in the fission yeast Schizosaccharomyces pombe

1985 ◽  
Vol 75 (1) ◽  
pp. 357-376 ◽  
Author(s):  
J.M. Mitchison ◽  
P. Nurse
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Cell Size ◽  
Single Cells ◽  
Temperature Shift ◽  
Time Lapse ◽  
Cell Length ◽  
Wild Type ◽  
Cycle Growth ◽  
A Cell ◽  
Mutant Cells

The cylindrical cells of Schizosaccharomyces pombe grow in length by extension at the ends and not the middle. At the beginning of the cell cycle, growth is restricted to the ‘old end’, which existed in the previous cycle. Later on, the ‘new end’, formed from the septum, starts to grow at a point in the cycle that we have called NETO (‘new end take-off’). Fluorescence microscopy on cells stained with Calcofluor has been used to study NETO in size mutants, in blocked cdc mutants and with different growth temperatures and media. In wild-type cells (strain 972) NETO happens at 0.34 of the cycle with a cell length of 9.5 microns. With size mutants that are smaller at division, NETO takes place at the same size (9.0-9.5 microns) but this is not achieved until later in the cycle. Another control operates in larger size mutants since NETO occurs at the same stage of the cycle (about 0.32) as in wild type but at a larger cell size. This control is probably a requirement to have completed an event in early G2, since most cdc mutant cells blocked before this point in the cycle do not show NETO whereas most of those blocked in late G2 do show it. We conclude that NETO only happens if: (1) the cell length is greater than a critical value of 9.0-9.5 microns; and (2) the cell has traversed the first 0.3-0.35 of the cycle and passed early G2. NETO is delayed in poor media, in which cell size is also reduced. Temperature has little effect on NETO under steady-state conditions, but there is a transient delay for some hours after a temperature shift. NETO is later in another wild-type strain, 132. Time-lapse photomicrography was used to follow the rates of length growth in single cells. Wild-type cells showed two linear segments during the first 75% of the cycle. There was a rate-change point (RCP), coincident with NETO, where the rate of total length extension increased by 35%. This increase was not due simply to the start of new-end growth, since old-end growth slowed down in some cells at the RCP. cdc 11.123 is a mutant in which septation and division is blocked at 35 degrees C but nuclear division continues.(ABSTRACT TRUNCATED AT 400 WORDS)

Ruthenium red: a highly efficient and versatile cell staining agent for single-cell analysis using inductively coupled plasma time-of-flight mass spectrometry

The Analyst ◽  
2021 ◽  
Author(s):  
Wen Qin ◽  
Hans-Joachim Stärk ◽  
Thorsten Reemtsma
Keyword(s):  
Inductively Coupled Plasma ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Ruthenium Red ◽  
Cell Analysis ◽  
Inductively Coupled ◽  
Flight Mass Spectrometry ◽  
Cell Staining ◽  
A Cell ◽  
Tof Ms

A new method for determining the concentration of elements in single cells by the SC-ICP-TOF-MS method based on a metal-containing stain as a cell volume proxy has been developed and validated.

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