• Food Science of Animal Resources
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• v.28 no.1
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• pp.63-68
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• 2008

To develop the somatic cell counting NIR Spectrum method within a range of 400-2500 nm, eosin-Y, methyl red, methylene blue, resazurin and amido black 10B were tested at 0.01% in raw milk. The PLS (Partial Least Square) results are summarized as follows: Correlation coefficients of the calibration model measurements by NIR spectroscopy in raw milk for eosin-Y, methyl red, methylene blue, resazurin and amido black 10B were 0.78, 0.65, 0.63, 0.65, 0.98 and 0.99, respectively. The correlation coefficients of the prediction model measurements by NIR spectroscopy in raw milk for eosin-Y, methyl red, methylene blue, resazurin and amido black 10B were 0.49, 0.21, 0.36, 0.47, 0.95 and 0.98 respectively. Based on these results, amido black 10B was the best additive for the NIRS somatic cell count method.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.48-55
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• 1989

The purpose of the present investigation was to improve several procedures being used in the adherence assay of Streptococcus sanguis cells to hydroxyapatite (HA) beads and to study the effect of the beads on the counting of radioactivity. The standard adhere assay involved the adherence of radiolabeled bacteria to 40mg of HA beads. The beads were mixed with ['H]thymidine-labeled bacterial cells and incubated for 60 minutes at room temperature. Unadsorbed cells were removed, the beads with adsorbed cells were dried, and the radioactivity was monitered in a scintillation spectrometer. The 30 seconds sonication of cells in a form of long chains appeared to be adequate for obtaining mostly singlet or doublet cells. Unlike the counting of S. sanguis cell suspension, bacterial cells adhered to HA or saliva-coated HA(SHA) required smaller volume (2.5ml) of scintillaton fluid for better counting. Eighteen percent quenching of counts could be attributed to the beads. Among 3 procedures commonly used to equilibrate the beads for adherence assay, no differences were found in their effectiveness. The HA beads on which the bacteria remained attached in scintillant during the counting were found to be the source of sample self-absorption representing 34.5% of the total radioactivity counts resulting from the beads dissolved in HCl solution.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.60-73
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• 2005

Objectives : The aim of this study was to evaluate the effects of Loranthus parasiticus Merr. on cell cycle and expression of related genes in HepG2 cells. Methods : The MTT assay, cell counting assay, $[^3H]-Thymidine$ incorporation assay, flow cytometric analysis, quantitative RT-PCR and western blot assay were studied. Results : In the water extract of Loranthus parasiticus Merr., inhibition of cell proliferation and DNA synthesis in HepG2 cells was seen. These inhibitory effects were due to inhibition of G l-S transition in cell cycle. After treatment with the extract, expression of cyclin D1(G1 check point related gene) was inhibited particularly in dose-dependent and time-dependent manners. Conclusion : These results suggest that the inhibition of cell cycle progression by Loranthus parasiticus Merr. in HepG2 cell is due to suppression of cyclin D1(G1 check point related gene) mRNA expression and protein synthesis.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.1
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• pp.103-113
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• 2019

Motivation: Polymerized actin-based cytoskeletal structures are crucial in shape, dynamics, and resilience of a cell. For example, dynamical actin-containing ruffles are located at leading edges of cells and have a significant impact on cell motility. Other filamentous actin (F-actin) bundles, called stress fibers, are essential in cell attachment and detachment. For this reason, their mechanistic understanding provides crucial information to solve practical problems related to cell interactions with materials in tissue engineering. Detecting and counting actin-based structures in a cellular ensemble is a fundamental first step. In this research, we suggest a new method to characterize F-actin wrapping fibers from confocal fluorescence image stacks. As fluorescently labeled F-actin often envelope the fibers, we first propose to segment these fibers by diminishing an energy based on maximum flow and minimum cut algorithm. The actual actin is detected through the use of bilateral filtering followed by a thresholding step. Later, concave actin bundles are detected through a graph-based procedure that actually determines if the considered actin filament is enclosing the fiber.

• Journal of Microbiology
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• v.44 no.5
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• pp.562-565
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• 2006

The cell counting of colonial Microcystis spp. is a rather difficult and error-prone proposition, as this genus forms irregularly-shaped and irregularly-sized colonies, which are packed with cells. Thus, in order to facilitate a cell count, four methods of dividing the colonies into single cells were compared, including vortexing, sonication, $TiO_2$ treatment, and boiling. As a result, the boiling method was determined to generate the greatest number of single cells from a colony, and all colonies were found to have divided completely after only 6 min of treatment. Furthermore, no significant cell destruction, which might alter the actual cell density, was detected in conjunction with the boiling method (P=0.158). In order to compute the cell number more simply, the relationship between the colony size and the cell number was determined, via the boiling method. The colony volume, rather than the area or diameter was correlated more closely with the cell number ($r^2=0.727$), thereby suggesting that the cell numbers of colonial Microcystis sp. can also be estimated effectively from their volumes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.12 s.243
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• pp.1615-1620
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• 2005

We present a novel flow-rate independent cell counter using a fixed control volume between double electrical sensing zones. The previous device based on the single electrical cell sensing in a given flow-rate requires an accurate fluid volume measurement or precision flow rate control. The present cell counter, however, offers the flow-rate independent method for the cell concentration measurement with counting cells in a fixed control volume of $22.9{\pm}0.98{\mu}{\ell}$. In the experimental study, using the RBC (Red Blood Cell), we have compared the measured RBC concentrations from the fabricated devices with those from Hemacytometer. The previous and present devices show the maximum errors of $20.3\%\;and\;16.1\%$, which are in the measurement error range of Hemacytometer (about $20\%$). The present device also shows the flow-rate independent performance at the constant flow-rates ($5{\mu}{\ell}/min$ and $10{\mu}{\ell}/min$) and the varying flow-rate (4, 2, and $4{\mu}{\ell}/min$). Therefore, we demonstrate that the present cell counter is a simple and automated method for the cell concentration measurement without requiring an accurate fluid measurement and precision flow-rate control.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.313-318
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• 2016

Bacteria in the viable but nonculturable (VBNC) state fail to produce colonies on routine bacteriological media, but are still alive in the state of very low metabolic activity. The aim of the present study was to induce the VBNC state of the Edwardsiella tarda using sea water microcosm under starvation conditions at $10^{\circ}C$ and to investigate resuscitation of the VBNC cells in temperatures changed from 10 to $25^{\circ}C$, with and without additives. E. tarda entered into the VBNC state within about 42-84 days of incubation in the microcosm. Throughout this period, the total cell counts as determined using acridine orange direct counting remained near the original inoculum level of ${\sim}10^8cells/ml$. The live cell counts measured with direct viable counting, on the other hands, declined to ${\sim}10^4cells/ml$. When the VBNC cells were incubated with addition of yeast extract, fish muscle extract or serum at $25^{\circ}C$, the ratios of resuscitated samples were 37%, 23%, and 37%, respectively. The characteristics of resuscitated E. tarda were consistent with those of the original E. tarda. When the resuscitated E. tarda were intraperitoneally injected into olive flounders, all fishes died within 5 days, indicating that the VBNC E. tarda might retain its pathogenic potential. Therefore, E. tarda under starvation conditions in the winter enter into the VBNC state and the VBNC E. tarda cells resuscitated at summer and autumn seawater temperature are considered to be pathogen continuously to olive flounder on the southern coast of Korea.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.48-59
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• 2005

Objectives : The aim of the study was to evaluate the effect of WS on HepG2 cell cycle and expression of related genes. Methods : The MTT assay, Cell counting analysis, $[^3H]-Thymidine$ Incorporation Assay, Flow cytometric analysis, Quantitative RT-PCR were studied. Results : WS inhibited HepG2 cell proliferation in low concentration$(1-10\;{\mu]g/ml)$ which did not cause direct cytotoxicity, with dose-dependant manner. WS in-hibited DNA synthesis as well. Flow cytometric analysis on the HepG2 cell showed G2/M phase arrest. Conclusion : These results suggest that WS inhibits HepG2 cell proliferation not by the gene regulation but by G2/M phase arrest in the cell cycle. Thus further studies on the effect of WS in G2/M phase regulation are thought to be needed.

• The Journal of the Korean dental association
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• v.55 no.9
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• pp.592-603
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• 2017

Purpose: The effects of various concentrations of ascorbic acid on stem cell spheroids derived from intraoral areas are not known yet. Thus, the purpose of this study is to evaluate the effects of different concentrations of ascorbic acid on the morphology and cellular viability of stem cell spheroids derived from the gingival tissues. Materials and Methods: Stem cells were plated onto silicon elastomer-based concave microwells and grown in the presence of ascorbic acid at concentrations ranging from 0.003% to 0.3%. The morphology of the cells was viewed under an inverted microscope at day 1, 2, 3 and 5. Qualitative live/dead assay and quantitative cellular viability using Cell Counting Kit-8 were performed on day 2 and day 5. Results: Gingiva-derived stem cells formed spheroids irrespective of ascorbic acid concentration in silicon elastomer-based concave microwells. Increase in the diameter of spheroid were seen with higher concentrations of ascorbic acid. Higher cellular viability was seen in higher concentrations of ascorbic acid. Conclusion: Within the experimental setting, the application of ascorbic acid on stem-cell spheroids produced an increase in the size and higher viability with higher dosage. It can be suggested ascorbic acid be applied with stem cell spheroids for tissue engineering purposes.

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.537-544
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• 2008

Polymerase chain reaction (PCR) can detect bacteria more rapidly than conventional plate counting. However DNA-based assays cannot distinguish between viable and dead cells due to persistence of DNA after cells have lost their vitality. Recently, propidium monoazide (PMA) treatment has been introduced. The purpose of this study is to evaluate the applicability of the PMA treatment and real-time PCR method for cell counting in comparison with plate counting and to evaluate the antibacterial efficacy of 2% CHX on E. faecalis using PMA treatment in combination with real-time PCR. Firstly, to elucidate the relationship between the proportion of viable cells and the real-time PCR signals after PMA treatment, mixtures with different ratios of viable and dead cells were used. Secondly, relative difference of viable cells using PMA treatment in combination with real-time PCR was compared with CFU by plate counting. Lastly, antibacterial efficacy of 2% CHX on E. faecalis was measured using PMA treatment in combination with real-time PCR. The results were as follows : 1. Ct value increased with decreasing proportion of viable E. faecalis. 2. There was correlation between viable cells measured by real-time PCR after PMA treatment and CFU by plate counting until Optical density (OD) value remains under 1.0. However, viable cells measured by real-time PCR after PMA treatment have decreased at 1.5 of OD value while CFU kept increasing. 3. Relative difference of viable E. faecalis decreased more after longer application of 2% CHX.