A study of changes in flocculence in a single cell culture of a strain of Saccharomyces cerevisiae

1963 ◽  
Vol 157 (967) ◽  
pp. 223-233 ◽  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Culture ◽  
Liquid Medium ◽  
Single Cell ◽  
Cell Cultures ◽  
Single Cells ◽  
Selective Advantage ◽  
Brewing Yeast ◽  
Flocculent Yeast ◽  
Single Cell Culture

A culture from a single cell of a flocculent brewing yeast became less flocculent during sub-culture on agar slopes. It was found that the culture had become a mixture of a number of variants differing in degree of flocculence. Five of the variants were studied using a sedi­-mentation method to measure flocculence. During subculture on agar and in liquid medium, single cell cultures of all these variants except the least flocculent gave rise to other variants. The proportion of less flocculent yeast increased during further subculture. The change was faster in liquid medium than on agar slopes. Yeast with more stable flocculence could be selected from the part of the population which did not change. Experiments with mixtures of ‘stable’ yeast indicated that the less flocculent yeast had a selective advantage, and that the mechanism of the selection involves the different physical properties of the yeast. All variants examined had the same rate of growth. Cultures derived from single cells of a given variant tended to give rise to the same new variants. Yeast with flocculence similar to the original strains could be isolated from the variant strains. It was not possible to determine whether these variants were produced by gene mutation since spore formation has never been detected in this yeast.

scholarly journals THE DIFFERENTIAL SENSITIVITY OF CULTURED CHICK MESODERMAL CELLS TO ACTINOMYCIN D

1969 ◽  
Vol 40 (1) ◽  
pp. 209-215 ◽  
Author(s):  
J. A. Piper ◽  
N. W. Klein
Keyword(s):  
Cell Culture ◽  
Single Cell ◽  
Cell Cultures ◽  
Actinomycin D ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Chick Embryos ◽  
Macromolecular Synthesis ◽  
Single Cell Culture

Cells were isolated from the somite mesoderm and from the unsegmented (presomite) mesoderm of early chick embryos and exposed to actinomycin D in single cell culture. Actinomycin D inhibited proliferation in cell cultures derived from the unsegmented mesoderm, although the same concentrations of this antibiotic did not inhibit cultures derived from the somite mesoderm. This differential sensitivity parallels the regionally specific necrosis and degeneration observed in the unsegmented mesoderm of intact chick embryos exposed to actinomycin D. In culture, both cell types exhibited approximately the same permeability to labeled actinomycin D and showed comparable inhibition of RNA, DNA, and protein syntheses in the presence of the antibiotic. However, freshly isolated mesodermal cells from the somite region had a higher content of RNA than did cells from the unsegmented region, and the somite cells maintained a higher rate of macromolecular synthesis in untreated cultures.

scholarly journals Chitosan Elicitation for Enhancing of Vincristine and Vinblastine Accumulation in Cell Culture of Catharanthus roseus (L.) G. Don

2018 ◽  
Vol 10 (12) ◽  
pp. 287
Author(s):  
Pawnpirun Pliankong ◽  
Padungsak Suksa-Ard ◽  
Surawit Wannakrairoj
Keyword(s):  
Molecular Weight ◽  
Cell Culture ◽  
Stationary Phase ◽  
Liquid Medium ◽  
Cell Cultures ◽  
Catharanthus Roseus ◽  
Dry Weight ◽  
Shrimp Shell ◽  
Anti Cancer ◽  
Herbal Plant

Catharanthus roseus (L.) G. Don is an important herbal plant. There are two important alkaloids, vinblastine and vincristine, use in anti-cancer drugs. In this study production of the two alkaloids was enhanced in C. roseus cell cultures, in a Murashige and Skoog (MS) liquid medium supplemented with 1.5 mg/L 2,4-D, 0.5 mg/L kinetin and 30 g/L sucrose, by adding 0, 50, 100, 250 or 500 mg/L medium molecular weight chitosan or chitosan derived from shrimp shell. After 14 days of culture, the cell suspension at stationary phase in the 100 mg/L medium molecular weight chitosan could produce the highest amounts of vinblastine and vincristine at 4.15 and 5.48 µg/mg cell dry weight, respectively. At the same time, the controls (0 mg/L chitosan) produced the two alkaloids at only 2.43 and 2.49 µg/mg cell dry weight, respectively. For chitosan from shrimp shell, it was found that 100 mg/L chitosan could lead to the highest quantity of 4.09 µg vinblastine/mg cell dry weight. The highest amount of 5.47 µg vincristine/mg cell dry weight was obtained when 250 mg/L chitosan was added.

scholarly journals Rapid and Simple Cryopreservation of Anaerobic Ammonium-Oxidizing Bacteria

2012 ◽  
Vol 78 (8) ◽  
pp. 3010-3013 ◽  
Author(s):  
Kim Heylen ◽  
Katharina Ettwig ◽  
Ziye Hu ◽  
Mike Jetten ◽  
Boran Kartal
Keyword(s):  
Cell Culture ◽  
Single Cell ◽  
Anammox Bacteria ◽  
Content Type ◽  
Growth Recovery ◽  
Activity Recovery ◽  
Simple Protocol ◽  
Single Cell Culture ◽  
Preservation Conditions

ABSTRACTA quick and simple protocol for long-term cryopreservation of anaerobic ammonium-oxidizing bacteria (anammox bacteria) was developed. After 29 weeks of preservation at −80°C, activity recovery for all tested cultures under at least one of the applied sets of preservation conditions was observed. Growth recovery was also demonstrated for a single-cell culture of “CandidatusKuenenia stuttgartiensis.”

scholarly journals Tracing blastomere fate choices of early embryos in single cell culture

2010 ◽  
Author(s):  
Mingyou Li ◽  
Jianxin Song ◽  
Yan Yan ◽  
Yongming Yuan ◽  
Chang Ming Li ◽  
...  
Keyword(s):  
Cell Culture ◽  
Single Cell ◽  
Early Embryos ◽  
Single Cell Culture

scholarly journals Colony formation of clone-sorted human hematopoietic progenitors

Blood ◽  
1990 ◽  
Vol 75 (10) ◽  
pp. 1941-1946 ◽  
Author(s):  
H Ema ◽  
T Suda ◽  
Y Miura ◽  
H Nakauchi
Keyword(s):  
Single Cell ◽  
Cell Cultures ◽  
Mononuclear Cells ◽  
Direct Action ◽  
Single Cells ◽  
Accurate Estimation ◽  
Hematopoietic Progenitors ◽  
Gm Csf ◽  
Cd34 Cells ◽  
Sorting System

Abstract To characterize human hematopoietic progenitors, we performed methylcellulose cultures of single cells isolated from a population of CD34+ cells by fluorescence-activated cell-sorting (FACS) clone-sorting system. CD34+ cells were detected in bone marrow (BM) and peripheral blood (PB) cells at incidences of 1.0% and 0.01% of total mononuclear cells, respectively. Single cell cultures revealed that approximately 37% of BM CD34+ cells formed colonies in the presence of phytohemagglutinin-leukocyte conditioned medium and erythropoietin. Erythroid bursts-, granulocyte-macrophage (GM) colony-, and pure macrophage (Mac) colony-forming cells were 10% each in CD34+ cells. Approximately 15% of PB CD34+ cells formed colonies in which erythroid bursts were predominant. CD34+ cells were heterogeneous and fractionated by several antibodies in FACS multicolor analysis. In these fractionated cells, CD34+, CD33+ cells formed GM and Mac colonies 7 to 10 times as often as CD34+, CD33- cells. Most of the erythroid bursts and colonies were observed in the fraction of CD34+, CD13- cells or CD34+, CD33- cells. The expression of HLA-DR on CD34+ cells was not related to the incidence, size, or type of colonies. There was no difference in the phenotypical heterogeneity of CD34+ cells between BM and PB. About 10% of CD34+ cells were able to form G colonies in response to granulocyte colony-stimulating factor (G-CSF) and to form Mac colonies in GM-CSF or interleukin-3 (IL-3). Progenitors capable of generating colonies by stimulation of G-CSF were more enriched in CD34+, CD33+ fraction than in CD34+, CD33- fraction. Thus, single cell cultures using the FACS clone-sorting system provide an accurate estimation of hematopoietic progenitors and an assay system for direct action of colony-stimulating factors.

scholarly journals AFM and Fluorescence Microscopy of Single Cells with Simultaneous Mechanical Stimulation via Electrically Stretchable Substrates

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4131
Author(s):  
Natalia Becerra ◽  
Barbara Salis ◽  
Mariateresa Tedesco ◽  
Susana Moreno Flores ◽  
Pasquale Vena ◽  
...  
Keyword(s):  
Cell Culture ◽  
Fluorescence Microscopy ◽  
Single Cell ◽  
Spatial Resolution ◽  
Single Cells ◽  
Optical Microscope ◽  
Average Cell ◽  
Atomic Force ◽  
Cell Stretcher

We have developed a novel experimental set-up that simultaneously, (i) applies static and dynamic deformations to adherent cells in culture, (ii) allows the visualization of cells under fluorescence microscopy, and (iii) allows atomic force microscopy nanoindentation measurements of the mechanical properties of the cells. The cell stretcher device relies on a dielectric elastomer film that can be electro-actuated and acts as the cell culture substrate. The shape and position of the electrodes actuating the film can be controlled by design in order to obtain specific deformations across the cell culture chamber. By using optical markers we characterized the strain fields under different electrode configurations and applied potentials. The combined setup, which includes the cell stretcher device, an atomic force microscope, and an inverted optical microscope, can assess in situ and with sub-micron spatial resolution single cell topography and elasticity, as well as ion fluxes, during the application of static deformations. Proof of performance on fibroblasts shows a reproducible increase in the average cell elastic modulus as a response to applied uniaxial stretch of just 4%. Additionally, high resolution topography and elasticity maps on a single fibroblast can be acquired while the cell is deformed, providing evidence of long-term instrumental stability. This study provides a proof-of-concept of a novel platform that allows in situ and real time investigation of single cell mechano-transduction phenomena with sub-cellular spatial resolution.

scholarly journals Improved single-cell culture achieved using micromolding in capillaries technology coupled with poly (HEMA)

2015 ◽  
Vol 9 (4) ◽  
pp. 044106 ◽  
Author(s):  
Fang Ye ◽  
Jin Jiang ◽  
Honglong Chang ◽  
Li Xie ◽  
Jinjun Deng ◽  
...  
Keyword(s):  
Cell Culture ◽  
Single Cell ◽  
Single Cell Culture ◽  
Micromolding In Capillaries
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