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

• Environmental Engineering Research
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• v.17 no.1
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• pp.35-39
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• 2012

In this study, multiparametric flow cytometry (FCM) was installed to enumerate the diagnosis of Pseudomonas aeruginosa ATCC 10145 and Escherichia coli K12 (IFO 3301). The nucleic acids (DNA/RNA) were double stained by a LIVE/DEAD bacLight viability kit, involving green SYTO 9 and red propidium iodide (PI), based on the permeability of two chemicals according to the integrity of plasma membrane. As the results showed, the gate for dead bacteria was defined as the range of $0.2{\times}10^0$ to $6.0{\times}10^1$ photo multiplier tube (PMT) 2 fluorescence (X-axis) and $2.0{\times}10^0$ to $2.0{\times}10^2$ PMT 4 fluorescence (Y-axis), and the gate for live bacteria was defined as the range of $6.0{\times}10^0$ to $6.0{\times}10^2$ PMT 2 fluorescence (X-axis) and $2.0{\times}10^0$ to $4.0{\times}10^2$ PMT 4 fluorescence (Y-axis). In the comparison of the number of the tested bacteria detected by FCM (viability assessment) and plate culture (cultivability assessment), the number of bacteria detected by FCM well represented the number of bacteria that was detected by the colony forming unit (CFU) counting method when bacteria were exposed to isopropyl alcohol and silver/copper cations. Consequently, it is concluded that the application of FCM to monitor the functional effect of disinfectants on the physiological status of target bacteria can offer more rapid and reliable data than the plate culture colony counting method.

• 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.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.329-335
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• 2008

This study was intended to research into the possibility of corilagin (CRN) isolated from Euphorbia helioscopia as rheumatoid arthritis drug. For the study, CRN was medicated to the abdominal cavity of collagen induced arthritis (CIA) mice that was a animal model for rheumatoid arthritis and its effects on incidence and arthritis index (AI) were studied. The results were as folllows; Medicating corilagin that were isolated from Euphorbia heliscopia to CIA mice resulted in inhibiting an incidence of arthritis and reducing in arthritis index. It was found that inflammatory cells were remarkably decreased and joint cavity was well secured. Also it was displayed that the formation of pannus was not observed and a cartilage was preserved well by cell histological research. Performing fluorescence flow cytometry of CIA mice resulted in reducing in inflammatory cells infiltrated each tissue.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.581-584
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• 2008

A generation of a particle beam is the key technique in a flow cytometry that measures the fluorescence and light scattering of individual cell and other particulate or molecular analytes in biomedical research. Recent methods performing this function require a laborious and time-consuming assembly. In the present work, we propose a novel device for the generation of an axisymmetrical focusing beam of microparticles (3-D focusing) in a single capillary without sheath flows. This work uses the concept that the particles migrate toward the centerline of the channel when they lag behind the parabolic velocity profile. Particle focusing of spherical particles was successfully made with a beam diameter of about 10 ${\mu}$m. Proposed device provides crucial solutions for simple and innovative 3-D particle focusing method for the applications to the MEMS-based micro-flow cytometry. We believe that this device can be utilized in a wide variety of applications, such as biomedical/ biochemical engineering.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.196-201
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• 1997

To characterize active cells during microspore culture of Angelica gigas, flow cytometric and epifluorescent techniques were applied. The knowledge obtained from these types of studies will give us insight into early stage in plant development and may lead to the application of microspore-derived from haploid plants for breeding in recalcitrant species. Viability of cultured microspore differed depending on the developmental stages. Frequencies of active cells from tetrad, uni-nucleate, bi-nucleate and matured pollen were 12.8, 49.3, 42.3 and 31.7%, respectively. Alive microspores have luminescent the green fluorescence stained with FDA and blue fluorescence stained with DAPI.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.290-294
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• 2006

Inactivation rates of Salmonella enteritidis in vitro and in vivo were assessed using confocal microscopy and flow cytometry. S. enteritidis was inactivated with 1% (w/v) trisodium phosphate (TSP) and live cells, and inactive cells were distinguished by staining with fluorescent probe, LIVE/DEAD BacLight Bacteria Viability stain. After TSP treatment for 1 min, most of Salmonella cells changed from green (live cells) fluorescence to red (inactive cells) fluorescence, indication of effective sanitizing. Inactivation efficiency and contamination sites of S. enteritidis on chicken skin by TSP treatment were assessed using confocal laser microscopy. Precise flow cytometry histograms for viability changes of S. enteritidis. after TSP treatments were obtained. Efficiency of various sanitizer treatments on foodborne pathogens could be assessed using this method.

• IMMUNE NETWORK
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• v.9 no.6
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• pp.243-247
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• 2009

In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.317-322
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• 2011

We determined the nuclear DNA content (genome size) of over 35 accessions each of bamboo and rattan species from Southeast Asia. The 2C DNA per nucleus was quantified by flow cytometry. The fluorescence of nuclei isolated from the leaves and stained with propidium iodide was measured. The genome size of the bamboo species examined was between 2.5 and 5.9 pg DNA per 2C nucleus. The genome size of the rattan species examined ranged from 1.8 to 10.5 pg DNA per 2C nucleus. This information will be useful for scientists working in diverse areas of plant biology such as biotechnology, biodiversity, genome analysis, plant breeding, physiology and molecular biology. Such data may be utilized to attempt to correlate the genome size with the ploidy status of bamboo species in cases where ploidy status has been reported.