• Molecules and Cells
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• v.26 no.4
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• pp.356-361
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• 2008

In this work, we have studied the structural and functional linkage between lamin A/C, nuclear actin, and organization of chromosome territories (CTs) in mammary carcinoma MCF-7 cells. Selective down-regulation of lamin A/C expression led to disruption of the lamin A/C perinuclear layer and disorganization of lamin-bound emerin complexes at the inner nuclear membrane. The silencing of lamin A/C expression resulted in a decrease in the volume and surface area of chromosome territories, especially in chromosomes with high heterochromatin content. Inhibition of actin polymerization led to relaxation of the structure of chromosome territories, and an increase in the volumes and surface areas of the chromosome territories of human chromosomes 1, 2 and 13. The results show an important role of polymeric actin in the organization of the nuclei and the chromosome territories.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.244-247
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• 2018

Quantitative analysis for non-host infection bacteriophage was conducted for their enumeration. Flow cytometry and epifluorescence microscopy (EPM) were selected as counting methods. Correlation analysis was performed based on the plaque assay method on the existing host infection and consisted of Pearson correlation statistical analysis, regression analysis, and difference analysis. Analyses of 12 samples with flow cytometry and plaque assay methods showed that there was a correlation of 96.7% with Pearson correlation value r=0.967, $R^2$ 0.9352, and difference value of 1.063. Analyses of 12 samples with EPM and plaque assay methods showed that there was a correlation of 99.0% with Pearson correlation value r=0.990, $R^2$ 0.9811, and difference value of 1.605. Therefore, flow cytometry and epifluorescence microscopy would be effective for enumeration of Weissella cibaria bacteriophage with plaque assay.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.221-226
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• 2017

Spermatozoa viability can be assessed by microscopy, flow cytometry, and other methods using fluorescent stain. Flow cytometry can be used to examine the morphological and functional characteristics of spermatozoa in a short time. The purpose of this study was to compare the viability of cryopreserved spermatozoa in Jeju black cattle by two dual fluorescent stain methods. Semen of Jeju black cattle raised in Subtropical Livestock Research Institute, National Institute of Animal Science, RDA were collected with artificial vaginal technique. Sperm was diluted with $Triladyl^{(R)}$-egg yolk diluent and then was performed cryopreservation. There was no significant difference in viability of spermatozoa according to the two dual fluorescent stain methods. However, when the distribution of spermatozoa according to the staining method was compared, the spermatozoa group stained with 6-CFDA/PI was more clearly distinguished than the spermatozoa group stained with calcein AM/PI.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4023-4027
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• 2012

Cytotoxicity assessment of silver nanoparticles (AgNPs) was performed using MTT-based microfluidic image cytometry (${\mu}FIC$). The $LC_{50}$ value of HeLa cells exposed to AgNPs in the microfluidic device was estimated as 46.7 mg/L, which is similar to that estimated by MTT-based IC for cells cultured in a 96 well plate (49.9 mg/L). These results confirm that the ${\mu}FIC$ approach can produce cytotoxicity data that is reasonably well-matched with that of the conventional 96 well plate system with much higher efficiency. This ${\mu}FIC$ method provides many benefits including ease of use and low cost, and is a more rapid in vitro cell based assay for AgNPs. This may aid in speeding up data acquisition in the field of nanosafety and make a significant contribution to the quantitative understanding of nanoproperty-toxicity relationships.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.345-351
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• 2003

Heptaplatin, cis-Malonato[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II), is a novel platinum-based antitumor agent with clinical potential against human stomach cancer and the 3rd generation of the cisplatin. This study was performed to study how cisplain, heptaplatin and sunpla which is a mixture of heptaplatin and mannitol (w: w=l : 2) affect cell viability of SK-MEL-28 human melanoma cell line. Heptaplatin ($IC_{50}$/; 95.35 $\mu$M) and sunpla ($IC_{50}$/; 10.95 11M) were less effect than cisplatin (IC $_{50}$; 10.92 $\mu$M) on the SK-MEL-28 cells. By cell cycle analysis using flow cytometry, it was identified that the cells were arrested at G2/M phase by cisplatin, heptaplatin and sunpla, and percentage of cell death group was increased according to increasing of time and concentration. These results suggest that cisplatin, heptaplatin and sunpla are a novel anticancer agent against human melanoma cell.l.

• ALGAE
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• v.31 no.4
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• pp.373-378
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• 2016

Cochlodinium polykrikoides is a red-tide forming dinoflagellate that causes significant worldwide impacts on aquaculture industries and the marine ecosystem. There have been extensive studies on managing and preventing C. polykrikoides blooms, but it has been difficult to identify an effective method to control the bloom development. There is also limited genome information on the molecular mechanisms involved in its various ecophysiology and metabolism processes. Thus, comprehensive genome information is required to better understand harmful algal blooms caused by C. polykrikoides. We estimated the C. polykrikoides genome size using flow cytometry, with detection of the fluorescence of DNA stained with propidium iodide (PI). The nuclear genome size of C. polykrikoides was 100.97 Gb, as calculated by comparing its mean fluorescence intensity (MFI) to the MFI of Mus musculus, which is 2.8 Gb. The exceptionally large genome size of C. polykrikoides might indicate its complex physiological and metabolic characteristics. Our optimized protocol for estimating the nuclear genome size of a dinoflagellate using flow cytometry with PI can be applied in studies of other marine organisms.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.1-6
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• 2012

This study evaluated a sexed sperm ability to produce embryos by flow cytometer. Hanwoo bulls sperm were separated to X and Y sperm via Hoechst 33342 stained with near UV laser or performed the pre-sorted without near UV laser beam in flow cytometry. Pre-sorted sperm had significantly higher viability ($84{\pm}1.15%$, $p$<0.05) compared to other sorted groups in frozen-thawed semen. For fresh semen, pre-sorted sperm had the higher viability ($79{\pm}3%$, $p$<0.05) than those of the X and Y sperm ($44.7{\pm}1.67$ and $41.7{\pm}1.2%$) separated by differences of DNA content. On the other hand, pre-sorted and X sperm sorted according to differences in DNA content had significantly higher viabilities ($24.3{\pm}1.2$ and $25.7{\pm}0.9%$, $p$<0.05) compared to that of the sorted Y sperm ($13.7{\pm}1.2%$) in the hypoosmotic swelling test. The proportion acrosome reaction in the sorted X sperm was higher ($55.0{\pm}1.7$ and $45.0{\pm}1.5%$) than those of the sorted Y-sperm ($32.3{\pm}0.9%$, $p$<0.05). However, the sperm morphologies of the sorted groups were not significantly differences. In conclusion, the sex-sorting procedure by flow cytometry affected some characteristics of Hanwoo sperm. Further study is needed to determine the optimal procedures to enhance male and female embryos and sorting accuracy.

• Osong Public Health and Research Perspectives
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• v.8 no.6
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• pp.389-396
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• 2017

Objectives: To circumvent the limitations of the current golden standard method, colony-forming unit (CFU) assay, for viability of Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccines, we developed a new method to rapidly and accurately determine the potency of BCG vaccines. Methods: Based on flow cytometry (FACS) and fluorescein diacetate (FDA) as the most appropriate fluorescent staining reagent, 17 lots of BCG vaccines for percutaneous administration and 5 lots of BCG vaccines for intradermal administration were analyzed in this study. The percentage of viable cells measured by flow cytometry along with the total number of organisms in BCG vaccines, as determined on a cell counter, was used to quantify the number of viable cells. Results: Pearson correlation coefficients of FACS and CFU assays for percutaneous and intradermal BCG vaccines were 0.6962 and 0.7428, respectively, indicating a high correlation. The coefficient of variation value of the FACS assay was less than 7%, which was 11 times lower than that of the CFU assay. Conclusion: This study contributes to the evaluation of new potency test method for FACS-based determination of viable cells in BCG vaccines. Accordingly, quality control of BCG vaccines can be significantly improved.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.199-205
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• 2019

Yeast two-hybrid (Y2H) technique has been used to study protein-protein interactions, but its application particularly to a large-scale analysis of protein interaction networks, is limited by the fact that the technique is labor-intensive, based on scoring colonies on plate. Here, we develop a new reporter for the measurement of the protein-protein interactions by flow cytometry. The yeast harboring interacting proteins can also be enriched by fluorescence-activated cell sorting (FACS) or magnetic-activated cell sorting (MACS). When two interacting proteins are present in the same yeast cell, a reporter protein containing 10 tandem repeats of c-myc epitope becomes localized on the surface of the cell wall, without affecting cell growth. We successful measured the surface display of c-myc epitope upon interacting p53 with SV40 T antigen by flow cytometry. Thus, the newly developed Y2H assay based on the display of c-myc repeat on yeast cell wall could be used to the simultaneous analysis of multiple protein-protein interactions without laborious counting colonies on plate.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.211-215
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• 2021

It is estimated that there are 40 million people with AIDS worldwide, with most cases occurring mainly in developing countries. HIV, the virus that causes AIDS, is infected with CD4+ T cells in the blood and gradually destroys CD4+ T cells for several months to 10 years, thereby lowering the patient's immune function. AIDS patients who have weakened immunity in this way will die from various diseases. The current method for counting the number of CD4+ T cells is usually performed by flow cytometry. The flow cytometry method has the advantage of high accuracy, but it is difficult to use in developing countries because it requires skilled professionals and equipment is expensive. As a result of this study, a device for AIDS screening was developed by capturing leukocytes from a small amount of 5 ㎕ blood through a microfilter and analyzing CD4+ T cells and CD8+ T cells from the captured cells. cheaper and easier to carry and use than current test equipment.