• Journal of Environmental Science International
• /
• v.26 no.1
• /
• pp.11-21
• /
• 2017

In this study, bacterial growth was assessed by flow cytometry analysis of fluorescent probes-stained bacteria. Flow cytometry has many advantages of rapid analytical time, a low standard deviation, and highly sensitive detection of live and Dead E.coli over colony forming assay. When untreated bacteria were stained by using Thiazole Orange (TO) and Propidium Iodide (PI), double staining had a short analytical time as compared with that of single staining while its error rate was similar to that of single staining. Through double staining experiments, it was determined that optimal concentrations for TO and PI staining were 420 nM and $9.6{\mu}M$, respectively.

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

• The Korean Journal of Cytopathology
• /
• v.8 no.1
• /
• pp.20-26
• /
• 1997

The specificity of cytologic examination in effusions is high but the sensitivity is low. Therefore, various ancillary methods for the detection of malignant cells in effusions have been proposed. The presence of an aneuploid cell population is generally considered diagnostic of malignancy. The purpose of this study is to determine whether the routine use of flow cytometry adds to standard cytologic evaluation in effusions. We did flow cytometric DNA analysis in 76 effusions(28 malignant and 48 benign fluids). All the 48 benign effusions were diploid. There were 12(42.9%) aneuploid and 16(67.1%) diploid malignant effusions. Based on these results flow cytometric DNA analysis had a sensitivity of 42.9% and a specificity of 100%. These results suggest that flow cytometric DNA analysis may be a useful adjunct to conventional cytology, but its principal limitation is us relatively low sensitivity.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.05a
• /
• pp.162-163
• /
• 1999

The goal of this research was (1) to describe the conditions and parameters required for the cell cycle synchronization and the accumulation of large number of metaphase cells in maize and other cereal root tips, (2) to isolate intact metaphase chromosomes from root tips suitable for characterization by flow cytometry, and (3) to construct chromosome-specific libraries from maize. Plant metaphase chromosomes have been successfully synchronized and isolated from many cereal root-tips. DNA synthesis inhibitor (hydroxyurea) was used to synchronize cell cycle, follwed by treatement with trifluralin to accumulate metaphase chromosomes. Maize flow karyotypes show substantial variation among inbred lines. thish variation should be sueful in isolating individual chromosome types. In addition, flow cytometry is a useful method to measure DNA content of individual chromosomes in a genotyps, and to detect chromosomal variations. Individual chromosome peaks have been sorted from the maize hybrid B73/Mol7. Libraries were generated form the DOP-PCR amplification product from each peak. To date, we have analyzed clones from a library constructed from the maize chromosome 1 peak. Hybridization of labeled genomic DNA to clone inserts indicated that $24\%,\;18\%,\;and\;58\%$ of the clones were highly repetitive, medium repetitive, and low copy, respectively. Fifty percent of putative low cpoy clones showed single bands on inbred screening, blots, and the remaining $50\%$ were low copy repeats. Single copy clones showing polymorphism will be mapped using recombinant inbred mapping populations. Repetitive clones are being characterized by Southern blot analysis, and will be screened by in situ hybridization for their potential utility as chromosome specific markers.

• Toxicological Research
• /
• v.25 no.3
• /
• pp.113-118
• /
• 2009

Cell death induced by menadione (vitamin K-3,2-methyl-1,4-naphthoquinone) has been investigated in human promyelocytic leukemia HL-60 cells. Menadione was found to induce both apoptosis and necrosis in HL-60 cells. Low concentration ($1{\sim}$50 ${\mu}$M) of menadione induced apoptotic cell death, which was demonstrated by typical DNA ladder patterns on agarose gel electrophoresis and flow cytometry analysis. In contrast, a high concentration of menadione (100 ${\mu}$M) induced necrotic cell death, which was demonstrated by DNA smear pattern in agarose gel electrophoresis. Necrotic cell death was accompanied with a great reduction of cell viability. Menadione activated caspase-3, as evidenced by both increased protease activity and proteolytic cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) into 85 kDa cleavage product. Caspase-3 activity was maximum at 50 ${\mu}$M of menadione, and very low at 100 ${\mu}$M of menadione. Taken together, our results showed that menadione induced mixed types of cell death, apoptosis at low concentrations and necrosis at high concentrations in HL-60 cells.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.112-119
• /
• 2005

Efficient plant regenerationsystem from cell suspension cultures was established in D. acicularis (2n = 90) by monitoring ploidy level and visual selection of the cultures. The highly regenerable cell lines selected maintained original ploidy level and consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7201-7205
• /
• 2014

Chemokine and chemokine receptor expression by tumor cells contributes to tumor growth and angiogenesis and thus these factors may be considered as tumor markers. Here we aimed to characterize cells directly extracted from glioma, meningioma, and secondary brain tumors as well as non-tumoral cells in vitro. Cells were isolated from brain tissues using 0.2% collagenase and characterized by flow cytometry. Expression of SDF-1, CXCR4, CXCR7, RANTES, CCR5, MCP-1 and IP-10 was defined using flow cytometry and qRT-PCR methods. Brain tissue isolated cells were observed as spindle-shaped cell populations. No significant differences were observed for expression of SDF-1, CXCR4, CXCR7, RANTES, CCR5, and IP-10 transcripts. However, the expression of CXCR4 was approximately 13-fold and 110-fold higher than its counterpart, CXCR7, in meningioma and glioma cells, respectively. CXCR7 was not detectable in secondary tumors but CXCR4 was expressed. In non tumoral cells, CXCR7 had 1.3-fold higher mRNA expression than CXCR4. Flow cytometry analyses of RANTES, MCP-1, IP-10, CCR5 and CXCR4 expression showed no significant difference between low and high grade gliomas. Differential expression of CXCR4 and CXCR7 in brain tumors derived cells compared to non-tumoral samples may have crucial impacts on therapeutic interventions targeting the SDF-1/CXCR4/CXCR7 axis.

• The Korean Journal of Malacology
• /
• v.28 no.1
• /
• pp.37-43
• /
• 2012

In this study, we invesgated a cytogenetic analysis of the Pacific triploid abalone, Haliotis discus hannai induced by low temperature treatment. We got a lot of mitotic metaphase chromosome spreads from the triploid and diploid Pacific abalones' hatched larvae (trochophores). The chromosome number of diploid abalone was 2n = 36 and that of triploid abalone was 3n = 54, so the chromosome number of triploid abalone was 1.5 times higher than that of diploid abalone. We developed a modified flow cytometric method for Pacific abalone from the existing methods. We uesd 51 months aged triploid and diploid Pacific abalones' hemolymph to get the DNA contents by flow cytometry. The DNA content of diploid abalone was 1.743 pg/cell and the DNA content of triploid abalone was 1.49 times higher than that of diploid one. It proved that triploid abalone was consisted with two sets of maternal diploid and one set of paternal genome.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.3
• /
• pp.261-266
• /
• 2019

Flow cytometry is an electrical detection system that provides precise and diverse optical properties to cells and micro particles. Flow cytometry, which provides multidimensional information including cell size and granularity through light scattering and fluorescence emission generated by the induction of light of a specific wavelength to the fluorescently treated cells or micro particles, plays an important role in biomedical and biophysical fields. However, it has some drawbacks such as high cost, size of the instrument and limitation in selecting fluorescent dyes. Therefore, in this paper, a low cost compact fluorescent detection system is developed using light-emitting diode and microcontroller. The proposed fluorescence detection system has a replaceable the light source/fluorescence filter/photodetector and constructed by 3D printer, so that the user can design a customized system according to the selected fluorescent dyes. The fluorescence intensity was measured by varying the number of fluorescently labeled cells, and the measured intensities showed a high linearity within the tested concentration ranges.

• Reproductive and Developmental Biology
• /
• v.30 no.1
• /
• pp.27-34
• /
• 2006

This study was conducted to compare the reproduction ability of the wild type boar and recombinant human erythropoietin (hEPO) transgenic boar semen. Ejaculated boar semen was analyzed by flow cytometry, Elisa and IVF methods. In experiment 1, flow cytometric analysis showed that the live sperm ratio of transgenic boar sperm significantly lower (P<0.05) than that of wild type boar after incubation at 20, 22, 24 and 26 hr. In experiment 2, the presence and levels of various cytokines (IL-6, IL-10 and $TNF-{\alpha}$) to related animal reproduction in the seminal and blood plasma were examined using specific enzyme immunoassay. There was no significant difference between both groups. In experiment 3, the fertilizing capacity and developmental ability of both boar sperm were compared. The transgenic boar sperm had a significantly low capacity of penetration, sperm-zona binding, embryo development, and blastocyst formation compared to wild type sperm (P<0.05). These results suggest that transgenic boar sperm harboring hEPO gene has low sperm viability than wild type boar, and it is a reason to decrease of fertility and litter size.