• Title/Summary/Keyword: Fluorescent assay

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Suppression of Bacterial Wilt with Fuorescent Pseudomonads, TS3-7 strain (Fluorescent siderophore 생산균주, TS3-7에 의한 풋마름병 발병 억제)

  • Kim, Ji-Tae;Cho, Hong-Bum;Kim, Shin-Duk
    • Applied Biological Chemistry
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    • v.48 no.3
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    • pp.296-300
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    • 2005
  • Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.

Fluorometric Determination of Gastric Acidity with 2-Fluorenecarboxaldehyde Hydrazone

  • Choi, Kyong;Choi, Jung-Kap;Yoo, Gyurng-Soo
    • Archives of Pharmacal Research
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    • v.17 no.4
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    • pp.231-235
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    • 1994
  • Fluorenecarboxaldehyde hydrazone 9FCH)was synthesized as a new fluorescent reagent for the determination of acidity. FCH had no fluorescence in itself, however, it strongly fluoresced under acidic conditions at excitation maximum of 392 nm and emission maximum of 447 nm, respectively. It showed good correlation with pH in the range from pH 0.60 to pH 3.60 in strong acids. As an application, the acidity of gastric juice in rats and humans was determined. In comparision with pH-metry, the acidity measured by the developed method showed generally increased values of about 0.7-1.3 unit and 0.8-1.2 unit in rats and humans, respectively. However, these results had statistically close correlation with those of pH-metry and the correlation coefficients were 0.887 in rats and humans between two methods.

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Detection of Escherichia coli Using Flow Cytometry (유세포 분석기를 이용한 대장균 검출에 관한 연구)

  • Kim, Ji-Hye;Park, Sang-Won;Cho, Young Sik
    • Journal of Environmental Science International
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    • v.26 no.1
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    • pp.11-21
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    • 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.

Replication and encapsidation of recombinant Turnip yellow mosaic virus RNA

  • Shin, Hyun-Il;Kim, In-Cheol;Cho, Tae-Ju
    • BMB Reports
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    • v.41 no.10
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    • pp.739-744
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    • 2008
  • Turnip yellow mosaic virus (TYMV) is a positive strand RNA virus that infects mainly Cruciferae plants. In this study, the TYMV genome was modified by inserting an extra subgenomic RNA promoter and a multiple cloning site. This modified TYMV was introduced into Nicotiana benthamiana using a Agrobacterium-mediated T-DNA transfer system (agroinfiltration). When a gene encoding $\beta$-glucuronidase or green fluorescent protein was expressed using this modified TYMV as a vector, replication of the recombinant viruses, especially the virus containing $\beta$-glucuronidase gene, was severely inhibited. The suppression of replication was reduced by co-expression of viral silencing suppressor genes, such as tombusviral p19, closteroviral p21 or potyviral HC-Pro. As expected, two subgenomic RNAs were produced from the recombinant TYMV, where the larger one contained the foreign gene. An RNase protection assay revealed that the recombinant subgenomic RNA was encapsidated as efficiently as the genuine subgenomic RNA.

Measurement of membrane fluidity of rockfish (Sebastes schlegeli) phagocytes during the respiratory burst using fluorescence polarization assay

  • Jung, Jae-Hyuck;Kwon, Se-Ryun;Lee, Eun-Hye;Kim, Sung-Mi;Kim, Ki-Hong
    • Journal of fish pathology
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    • v.16 no.2
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    • pp.131-134
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    • 2003
  • The change of membrane fluidity in rockfish (Sebastes schlegeli) phagocytes during respiratory burst was investigated. Fluorescence polarization (FP) was used as a measure of membrane fluidity, and 1-(4-trimethylaminophenyl)-6-phenyl-1 .3 ,5-hexatriene (TMA.-DPH) was used us a fluorescent probe. The significantly higher FP values in phagocytes stimulated With zymosan or phurbol myristate acetate (PMA) than unstimulated control phagocytes suggests that membrane fluidity of phagocytcs is decreased during the respiratory burst. The faster decrease of FP value in PMA stimulated phagocytes than in zymosan sumulated phagocytes may be due to bypass of the receptor-mediated stages of functional modulation. which is needed in zymosan stimulated phagocytes.

Anti-proliferating Effects of Some Plants on the Hepatoma Cell (수종 식물들의 Hepatoma cell 증식 저해작용)

  • Chung, Yong Za;Lee, Un Joo
    • Korean Journal of Clinical Pharmacy
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    • v.9 no.2
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    • pp.103-108
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    • 1999
  • The anti-proliferating effects of some plants on hepatoma cell lines were studied by the 3-[4,5-dim-ethylthiazol-2yl]-2,5-diphenyl-tetrazolium bromide (MTT assay), to investigate the anticancer effect with some plants around here. As the result, we saw that the anti-prolferating effect to the plants. Among the plants, Equisetum arvense L. and Lactuca dentata Makino. var, flaviflora Makino of them relatively showed a good ant-proliferating effect. Capsicum annuum L. var. angulosum Mill (Leaf) was the best among them. We also examined morphological changes on the hepatoma cells in this process. In case of Capxicum annuum L. var. angulosum Mill, the tells become vague after 2 days, and then destroyed faster than others. We can fee also the condensated chromosome on the treated cells with Capxicum annuum L. var. angulosum Mill. And we also observed condensation through using a fluorescent microscope by PI staining, and observed DNA fragmentation.

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Novel Real Time PCR Method for Detection of Plasmodium vivax (새로운 Real Time PCR 방법을 통한 Malaria(Plasmodium vivax)의 검출)

  • Ki, Yeon-Ah;Kim, So-Youn
    • Microbiology and Biotechnology Letters
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    • v.33 no.2
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    • pp.148-153
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    • 2005
  • Malaria is a re-emerging infectious disease that is spreading to areas where it had been eradicated, such as Eastern Europe and Central Asia. To avoid the mortality from malaria, early detection of the parasite is a very important issue. The peripheral blood smear has been the gold standard method for the diagnosis of malaria infection. Recently, several other methods have been introduced for quantitative detection of malaria parasites. Real time PCR that employs fluorescent labels to enable the continuous monitoring of PCR product formation throughout the reaction has recently been used to detect several human malaria parasites. 18S rRNA sequences from malaria parasites have been amplified using Taqman real time PCR assay. Here, a SYBR Green-based real time quantitative PCR assay for the detection of malaria parasite-especially, Plasmodium vivax - was applied for the evaluation of 26 blood samples from Korean malaria patients. Even though SYBR Green-based real time PCR is easier and cheaper than Taqman-based assay, SYBR Green-based assay cannot be used because 18S rRNA cannot be specifically amplified using 1 primer set. Therefore, we used DBP gene sequences from Plasmodium vivax, which is specific for the SYBR Green based assays. We amplified the DBP gene from the 26 blood samples of malaria patients using SYBR Green based assay and obtained the copy numbers of DBP genes for each sample. Also, we selected optimal reference gene between ACTB and B2M using real time assay to get the stable genes regardless of Malaria titer. Using selected ACTB reference genes, we successfully converted the copy numbers from samples into titer, ${\sharp}$ of parasites per microliter. Using the resultant titer from DBP based SYBER Green assay with ACTB reference gene, we compared the results from our study with the titer from Taqman-based assay. We found that our results showed identical tendency with the results of 18S rRNA Taqman assay, especially in lower titer range. Thus, our DBP gene-utilized real time assay can detect Plasmodium vivax in Korean patient group semi-quantitatively and easily.

Validation of Gene Silencing Using RNA Interference in Buffalo Granulosa Cells

  • Monga, Rachna;Datta, Tirtha Kumar;Singh, Dheer
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.11
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    • pp.1529-1540
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    • 2011
  • Silencing of a specific gene using RNAi (RNA interference) is a valuable tool for functional analysis of a target gene. However, information on RNAi for analysis of gene function in farm animals is relatively nil. In the present study, we have validated the interfering effects of siRNA (small interfering RNA) using both quantitative and qualitative gene silencing in buffalo granulosa cells. Qualitative gene knockdown was validated using a fluorescent vector, enhanced green fluorescence protein (EGFP) and fluorescently labeled siRNA (Cy3) duplex. While quantitatively, siRNA targeted against the luciferase and CYP19 mRNA was used to validate the technique. CYP19 gene, a candidate fertility gene, was selected as a model to demonstrate the technique optimization. However, to sustain the expression of CYP19 gene in culture conditions using serum is difficult because granulosa cells have the tendency to luteinize in presence of serum. Therefore, serum free culture conditions were optimized for transfection and were found to be more suitable for the maintenance of CYP19 gene transcripts in comparison to culture conditions with serum. Decline in fluorescence intensity of green fluorescent protein (EGFP) was observed following co-transfection with plasmid generating siRNA targeted against EGFP gene. Quantitative decrease in luminescence was seen when co-transfected with siRNA against the luciferase gene. A significant suppressive effect on the mRNA levels of CYP19 gene at 100 nM siRNA concentration was observed. Also, measurement of estradiol levels using ELISA (enzyme-linked immunosorbent assay) showed a significant decline in comparison to control. In conclusion, the present study validated gene silencing using RNAi in cultured buffalo granulosa cells which can be used as an effective tool for functional analysis of target genes.

In Vitro Infectivity Assessment by Drug Susceptibility Comparison of Recombinant Leishmania major Expressing Enhanced Green Fluorescent Protein or EGFP-Luciferase Fused Genes with Wild-Type Parasite

  • Sadeghi, Somayeh;Seyed, Negar;Etemadzadeh, Mohammad-Hossein;Abediankenari, Saeid;Rafati, Sima;Taheri, Tahereh
    • Parasites, Hosts and Diseases
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    • v.53 no.4
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    • pp.385-394
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    • 2015
  • Leishmaniasis is a worldwide uncontrolled parasitic disease due to the lack of effective drug and vaccine. To speed up effective drug development, we need powerful methods to rapidly assess drug effectiveness against the intracellular form of Leishmania in high throughput assays. Reporter gene technology has proven to be an excellent tool for drug screening in vitro. The effects of reporter proteins on parasite infectivity should be identified both in vitro and in vivo. In this research, we initially compared the infectivity rate of recombinant Leishmania major expressing stably enhanced green fluorescent protein (EGFP) alone or EGFP-luciferase (EGFP-LUC) with the wild-type strain. Next, we evaluated the sensitivity of these parasites to amphotericin B (AmB) as a standard drug in 2 parasitic phases, promastigote and amastigote. This comparison was made by MTT and nitric oxide (NO) assay and by quantifying the specific signals derived from reporter genes like EGFP intensity and luciferase activity. To study the amastigote form, both B10R and THP-1 macrophage cell lines were infected in the stationary phase and were exposed to AmB at different time points. Our results clearly revealed that the 3 parasite lines had similar in vitro infectivity rates with comparable parasite-induced levels of NO following interferon-${\gamma}$/lipopolysaccharide induction. Based on our results we proposed the more reporter gene, the faster and more sensitive evaluation of the drug efficiency.

Production and characterization of monoclonal antibodies against rabies virus (광견병바이러스에 대한 단크론항체 생산 및 특성)

  • Lee, Seung-Chul;Yoon, Young-Sim;Song, Yun-Kyung;Woo, Gye-Hyeong;Jean, Young-Hwa;Kang, Shien-Young
    • Korean Journal of Veterinary Service
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    • v.33 no.2
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    • pp.105-111
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    • 2010
  • Rabies virus which belongs to the genus Lyssavirus of the family Rhabdoviridae is known as a highly neurotropic virus and causes fatal encephalitis accompanied by severe neurological symptoms in almost all mammals, including humans. In this study, monoclonal antibodies (MAbs) against rabies virus were produced, characterized and applications of MAbs as diagnostic reagents were assessed Spleen and inguinal lymph node cells from Balb/c mouse immunized with purified rabies virus were fused with SP2/O myeloma cells using polyethylene glycol (PEG) and hybridoma cells producing rabies virus-specific MAbs were screened by an indirect fluorescent antibody test. A total of ten MAbs were produced against rabies virus. The protein specificity and neutralizing activity of MAbs were determined by Western blot analysis and fluorescent antibody virus neutralization test, respectively. As a result, two MAbs, 5G3 and 6H4 had specificity for nucleoprotein (N protein) and two other MAbs, 5B1 and 5C1 had neutralizing activity for rabies virus. Some MAbs recognized the rabies virus-infected bovine brain stem cells by immunohistochemistry (IHC) assay. In conclusion, it was confirmed that MAbs produced in this study were rabies virusspecific and could be used as reliable diagnostic reagents for the detection of rabies virus.