Papers by Keyword: Flow Cytometry

Abstract: In-situ realtime method that can monitor the target bacteria should be used to determine the real situation of the bacteria in deep parts of heaps in heap bioleaching plants. This study suggest to apply flow cytometry technology to in-situ realtime monitoring of target bacteria. Flow cytometry is a method that can rapidly quantify the bacterial cells in bacterial suspension based on the detection of lights that are emitted from bacterial cells. In this study, we estimated the possibility of the application of flow cytometry to the selective detection of target bacteria. The bacterial culture solution that had been diluted by water including other bacteria was provided for fluorescence spectral analysis and scattered light analysis that were functions of flow cytometry. Our target bacteria could be selectively detected by those analyses in this study, therefore, it was shown that the flow cytometry could be useful for detecting target bacteria selectively. Because the measurement principle of flow cytometry is quite simple, it can be expected to be installed into deep heaps through the monitoring wells and determine the dominance of target bacteria in-situ and realtime in the future.

Abstract: In this paper, the binding assay of potential aptamer candidates targeted to L. acidophilus was monitored by flow cytometry. Furthermore, the equilibrium dissociation constant of the aptamer-bacterial cell interaction were estimated.

Abstract: Flow cytometry is a examination method which can analyse and sort unicellular or biological particles . For the requirement of the width and the flowage of sample flow in the laser detection area , this paper designs a sheath flow system of flow cytometry through solidworks software based on the theory of hydrodynamic focusing. Simulating and calculating this model through solidworks flow simulation software, the simulated results meet fully the actual experiment for unicellular and biological particles. The simulated results can verify the correctness of the sheath flow system, and it has certain theoretical significance for actual design of sheath system about flow cytometry.

Abstract: As for the requirement of size and energy distribution of focal spot in the laser detection area, this paper designs a laser beam-shaping system of flow cytometry. The 640nm red diode laser and 488nm blue solid laser which are arranged vertically are used as the excitation source. The emergent ray of two lasers is combined by beam splitter, and the combined beam is focused on the screen through two orthogonal cylindrical lens. The focal spot is compressed by doublet lens which is also used to eliminate chromatic aberration of focal spot. Applying ZEMAX software to optimize the whole optical system, the simulated results meet fully the actual experiment for individual blood cells, and it has certain theoretical significance for actual design of optical system about flow cytometry.

Abstract: Objective:To study the effect of oxymatrine on apoptosis of human carcinoma cell line MGC-803. Methods:Flow cytometry were conducted to investigate apoptosis rate and expression of Bcl-2 and Bax protein. Results: At the dose of oxymatrine were 1mg/ml,2mg/ml,the apoptosis rates in MGC-803 were higher than those of controls (p<0.05), the expression of Bcl-2 was decreased and Bax was increased significantly (p<0.05).Conclusion:Oxymatrine induces apoptosis in human carcinoma cell line MGC-803, its mechanism includes up-regulated expression of Bax and down-regulated expression of Bcl-2.

Abstract: Flow cytometry was applied in the study of the groups and spatial distribution characteristics of the fine particles in Bantou—Shidou Reservoir, a subtropical reservoir in Xiamen,China. The fine organic autotrophic particles in reservoir could be divided into four groups conspicuously: R2 group in the smallest size with much phycoerythrin but little chlorophyll; R1 and R4 groups in relatively large size: R1 group with certain phycoerythrin and chlorophyll, while R4 group with no phycoerythrin but much chlorophyll; R3 group in the largest size with certain phycoerythrin and a large amount of chlorophyll. All the sampling stations in Shidou ( upper reaches) and Bantou ( lower reaches) reservoirs contain maximum R1 group with quantity between 35.41-46.85×106 ind/L and 23.39-43.02×106 ind/L; and minimum R3 group with quantity between 0.20-0.58×106 ind/L and 0.22-0.78×106 ind/L. The quantity of fine organic autotrophic particles is larger than that of organic azoic particles and inorganic particles. In view of the spatial distribution, R1 and R3 groups distribute unevenly in Shidou reservoir, while R2 and R4 groups change a little in quantity in different sampling stations and distribute much evenly. Moreover, in Bantou reservoir, R1, R2 and R3 groups distribute unevenly in the sampling stations, while R4 group distributes relatively evenly. The fast and multi-parameter detection capacity of Flow cytometry provides a much effective mean for the research on water fine organic autotrophic particles.

Abstract: The fine combination of biomaterial and essential cells determines a successful artificial graft. With high biocompatibility, chitosan is a choice of materials for regeneration medicine. In the peripheral nervous system, Schwann cells are critical for nerve regeneration. Schwann cells not only help to conduct the nerve pulse but also guide the nerve extension, especially the injured nerve for recovery. Studies showed that chitosan can be a bridge material for damaged nerve regeneration. The interactions between chitosan and Schwann cells may provide important information for designing the chitosan grafts applied in medical applications. For this purpose, the chitoson was made into conduits by lyophilization. The conduit has porous 3D scaffolds and seeded with rat Schwann cells. The harvested cells were labeled with PI fluorescent dye and analyzed with flow cytometry. The results showed that the rates of DNA replication (S-phase) and cell division (G2 phase) of the cells grew on chitosan scaffolds were higher than the ones grew on the plane substrate. This indicates that the cells grew on chitosan scaffolds were more active than those on the plane substrate in cell proliferation, and the biocompatibility of chitosan can be sustained in this quantitative analysis. Therefore, chitosan scaffolds are efficient for cell expansion of rat Schwann cells and may be beneficial for the purpose of tissue engineering. This study proves that cell cycle analysis is a new point of view in disclosing the cell-material interactions.

Abstract: The distribution and activity of cell receptors, which are key factors of baculovirus-insect cell interactions, may be attributed to cell cycle. In fact, the virtual difference in time of infection is the difference in cell cycle distribution. In this work, the effects of cell cycle on cell activity and baculovirus production were investigated. Sf9 cells were infected with baculovirus at the different cycle phases. It was found that G1 phase plays a substantial role in cell activity and competence for the baculovirus replication. Sf9 cells have the highest succinate dehydrogenase activity and are most sensitive for the baculovirus replication when the proportion of G1 phase in cell population reaches a maximum. On the hand, cell activity is at the lowest when G2/M percentage reaches its maximum. These results provide a guidance in developing the baculovirus infection dynamics model and controlling the expression of useful foreign genes when cell cycle is taken into account.

Abstract: The ploidy of parthenogenetic Artemia from Aqqikkol Hu (Xinjiang) was determinated by flow cytometry. The results showed that the Artemia populaton of Aqqikkol Hu (Xinjiang) consisted diploid and tetraploid, the rate of diploid and tetraploid approximated to 80% and 20% respectively. It should conclude that the results of ploidy of parthenogenetic Artemia can be determinated rapidly and exactly by flow cytometry. The new method for the ploidy determination of parthenogenetic Artemia should accumulate the basic data for biological study and application of Artemia.

Abstract: To investigate nanoparticles’ antitumor effect, a globose 30~35nm Ce(IV) doped Titanium dioxide nanoparticles (CDT) were prepared by impregnation method and characterized by X-ray diffraction (XRD) and transmission electron microscopy(TEM). Proliferation of BEL7402 human Hepatoma cells was studied in vitro by using fluorescence microscopy and Flow Cytometry. The results show that cerium elements doping enhanced thermal stability of nano-size titanium dioxide to 800°C. With UV irradiated for 8min, BEL7402 were induced a dose-dependent apoptosis by CDT, about 28.2% , 41.5% and 88.3% cells were induced apoptosis after 24h at concentration of 60, 120 and 180ug/ml respectively, relative to 3.9% of that of control group cell just only in the presence of UV.