Displaying publications 1 - 20 of 218 in total

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  1. Ho SY, Goh CW, Gan JY, Lee YS, Lam MK, Hong N, et al.
    Zebrafish, 2014 Oct;11(5):407-20.
    PMID: 24967707 DOI: 10.1089/zeb.2013.0879
    Existing zebrafish embryonic stem (ES) cell lines are derived and maintained using feeder layers. We describe here the derivation and long-term culture of an ES cell-like line derived from zebrafish blastomeres without the use of feeder cells. This line, designated as ZES1, has been maintained for more than 800 days in defined Dulbecco's modified Eagle's medium supplemented with fetal bovine serum, zebrafish embryo extract, trout serum, and human basic fibroblast growth factor. ZES1 cells possessed a morphology typical of ES cells, being round or polygonal in shape with a large nucleus and sparse cytoplasm and were mostly diploid. The cells formed individual colonies consisting of tightly packed cells that stained positively for alkaline phosphatase. ZES1 cells also formed embryoid bodies when transferred onto uncoated wells. The pluripotent nature of ZES1 cells was confirmed when they could be induced to differentiate in vitro into several cell types, through low- or high-density culture conditions. Treatment with retinoic acid also induced the differentiation of ZES1 cells into primarily neuronal cells. Using immunostaining and real-time polymerase chain reaction, we showed that Sox2, a known pluripotent marker in mammalian ES cells, was also present in ZES1 cells. Chimera experiments revealed that fluorescent-labeled ZES1 cells microinjected into zebrafish blastulas participated in the formation of all three germ layers. Using GFP-labeled ZES1 cells, chimera germline transmission was also demonstrated at the F1 generation. In conclusion, ZES1 cells possess both in vitro and in vivo pluripotency characteristics, indicating that nonmammalian ES cells can be readily derived and maintained for a long term under feeder-free culture conditions.
    Matched MeSH terms: Cell Culture Techniques/methods*
  2. Hani H, Ibrahim TA, Othman AM, Lila MA, bt Allaudin ZN
    Xenotransplantation, 2010 12 17;17(6):469-80.
    PMID: 21158948 DOI: 10.1111/j.1399-3089.2010.00616.x
    BACKGROUND: Insufficient availability of human donors makes the search for alternative source of islet cells mandatory for future developments in pancreatic transplantation. The present study investigates the potential of caprine as an alternative source of pancreatic islets. The objectives of the study were to optimize techniques for caprine islet isolation and purification for culture establishment, and to subsequently assess their viable and functional potential.

    METHODS: Caprine pancreatic tissues were collected from a local slaughterhouse and prior transported to the laboratory by maintaining the cold chain. Islets were obtained by a collagenase-based digestion and optimized isolation technique. Islet cell purity and viability were determined by dithizone and trypan blue staining, respectively. Islet clusters of different sizes were positively identified by staining methods and demonstrated 90% viability in the culture system. Following static incubation, an in vitro insulin secretion assay was carried out and analyzed by ELISA.

    RESULTS: The islets remained satisfactorily viable for 5 days in the culture system following regular media changes. The current study has successfully optimized the isolation, purification and culture maintenance of caprine islets.

    CONCLUSION: The successful yield, viability and functionality of islets isolated from the optimized protocol provide promising potential as an alternative source of islets for diabetes and transplantation researches.

    Matched MeSH terms: Cell Culture Techniques
  3. Ong YH, Chua AS, Lee BP, Ngoh GC
    Water Sci Technol, 2013;67(2):340-6.
    PMID: 23168633 DOI: 10.2166/wst.2012.552
    To date, little information is known about the operation of the enhanced biological phosphorus removal (EBPR) process in tropical climates. Along with the global concerns on nutrient pollution and the increasing array of local regulatory requirements, the applicability and compliance accountability of the EBPR process for sewage treatment in tropical climates is being evaluated. A sequencing batch reactor (SBR) inoculated with seed sludge from a conventional activated sludge (CAS) process was successfully acclimatized to EBPR conditions at 28 °C after 13 days' operation. Enrichment of Candidatus Accumulibacter phosphatis in the SBR was confirmed through fluorescence in situ hybridization (FISH). The effects of operational pH and influent C:P ratio on EBPR were then investigated. At pH 7 or pH 8, phosphorus removal rates of the EBPR processes were relatively higher when operated at C:P ratio of 3 than C:P ratio of 10, with 0.019-0.020 and 0.011-0.012 g-P/g-MLVSS•day respectively. One-year operation of the 28 °C EBPR process at C:P ratio of 3 and pH 8 demonstrated stable phosphorus removal rate of 0.020 ± 0.003 g-P/g-MLVSS•day, corresponding to effluent with phosphorus concentration <0.5 mg/L. This study provides the first evidence on good EBPR activity at relatively high temperature, indicating its applicability in a tropical climate.
    Matched MeSH terms: Batch Cell Culture Techniques
  4. Johan CAC, Zainathan SC
    Vet World, 2020 Nov;13(11):2565-2577.
    PMID: 33363355 DOI: 10.14202/vetworld.2020.2565-2577
    Iridoviruses, especially megalocytiviruses, are related to severe disease resulting in high economic losses in the aquaculture industry worldwide. The ornamental fish industry has been affected severely due to Megalocytivirus infections. Megalocytivirus is a DNA virus that has three genera; including red sea bream iridovirus, infectious spleen and kidney necrosis virus, and turbot reddish body iridovirus. Megalocytivirus causes non-specific clinical signs in ornamental fish. Cell culture, histology, immunofluorescence test, polymerase chain reaction (PCR) assay, and loop-mediated isothermal amplification assay have been used to diagnose megalocytiviruses. Risk factors such as temperature, transportation (export and import), and life stages of ornamental fish have been reported for the previous cases due to Megalocytivirus infections. In addition, other prevention and control methods also have been practiced in farms to prevent Megalocytivirus outbreaks. This is the first review of megalocytiviruses in ornamental fish since its first detection in 1989. This review discusses the occurrences of Megalocytivirus in ornamental fish, including the history, clinical signs, detection method, risk factors, and prevention measures.
    Matched MeSH terms: Cell Culture Techniques
  5. Poobathy, Ranjetta, Rahmad Zakaria, Syed Mohd. Edzham Syed Hamzah, Subramaniam, Sreeramanan
    Trop Life Sci Res, 2016;27(11):15-19.
    MyJurnal
    The terrestrial Ludisia discolor, also referred to as the jewel orchid is prized for
    the quality of its leaves. L. discolor is known as a medicinal herb and is touted for its heatand
    pathogen-resisting qualities. L. discolor is valuable in the production of both flavonoids
    and anthocyanins, antioxidants that are exalted in the health industry. Plant cell cultures
    have emerged as alternative sources of anthocyanin production. Plant protoplast cultures
    are used frequently in transient gene expression studies and in the establishment of callus
    and cell suspension cultures. Benefits of plant protoplast system include similarity to cells
    found in plant tissues, reproduction under controlled conditions, and prevention of masking
    of stress responses to previous handling techniques. A study was conducted to assess the
    amenability of the stem and leaves of L. discolor to protoplast isolation. The stem and leaf
    segments were weighed, sliced into thin layers, immersed in a digestion medium, washed
    and then cultured onto a recovery medium. Results indicated that the production of plant
    protoplasts from L. discolor may be viewed as an alternative in the generation of cell
    cultures and ultimately in the production of anthocyanins from the cell cultures.
    Matched MeSH terms: Cell Culture Techniques
  6. Saadatnia G, Haj Ghani H, Khoo BY, Maimunah A, Rahmah N
    Trop Biomed, 2010 Apr;27(1):125-30.
    PMID: 20562822
    In vitro culture of Toxoplasma gondii can provide tachyzoites which are active, viable and with desirable purity. Thus the aim of this study was to optimize the cell culture method for T. gondii propagation to obtain a consistent source of parasites with maximum yield and viability, but minimum host cell contamination for use in production of excretory-secretory antigen. Tachyzoites with seed counts of 1x10(6), 1x10(7) and 1x10(8) harvested from infected mice were added to VERO cells of different degrees of confluence, namely 50%, 85% and 100%, and examined periodically using an inverted microscope. When the maximum release of the tachyzoites was observed from the host cells, the culture supernatant was removed and the tachyzoites harvested. Using a Neubauer chamber, the percentages of viable tachyzoites and host cell contamination were determined using trypan blue stain. Parameters that gave the best yield and purity of viable tachyzoites were found to be as follows: VERO cells at 85% confluence in DMEM medium and inoculum comprising 1x10(7) tachyzoites. After about 3 days post infection, the tachyzoites multiplied 78x, with a yield of ~7.8x10(8) per flask, 99% viability and 3% host cell contamination. This study has successfully optimized the method of propagation of T. gondii tachyzoites in VERO cells which produce parasites with high yield, purity and viability.
    Matched MeSH terms: Cell Culture Techniques/methods*
  7. Suriyanti SN, Usup G
    Toxicon, 2015 Dec 15;108:257-63.
    PMID: 26541573 DOI: 10.1016/j.toxicon.2015.10.017
    Screening of the occurrence of potentially toxic diatoms was carried out at two sites of cage cultures in Tebrau Straits, Johor. Phytoplankton samples from Sungai Pendas and Teluk Sengat were collected using a 20 μm mesh plankton net and salinity was recorded in-situ. Nitzschia and Pseudo-nitzschia cells were isolated and established into clonal cultures. All cultures were tested for domoic acid using HPLC-UV analysis and verified by LC-MS analysis. Three Nitzschia spp. and one Pseudo-nitzschia sp. were identified from these locations. Toxic and non-toxic strains of Nitzschia navis-varingica are found at the cage culture areas. Cellular toxin content in the toxic strain of N. navis-varingica is 1.8 pg cell(-1). This is a new record from Malaysia and this species was isolated from estuarine water with salinity 28 PSU. The discovery of toxic Nitzschia species in Tebrau Straits indicates the potential for domoic acid accumulation in seafood.
    Matched MeSH terms: Cell Culture Techniques
  8. Um Min Allah N, Berahim Z, Ahmad A, Kannan TP
    Tissue Eng Regen Med, 2017 Oct;14(5):495-505.
    PMID: 30603504 DOI: 10.1007/s13770-017-0065-y
    Advancement in cell culture protocols, multidisciplinary research approach, and the need of clinical implication to reconstruct damaged or diseased tissues has led to the establishment of three-dimensional (3D) test systems for regeneration and repair. Regenerative therapies, including dental tissue engineering, have been pursued as a new prospect to repair and rebuild the diseased/lost oral tissues. Interactions between the different cell types, growth factors, and extracellular matrix components involved in angiogenesis are vital in the mechanisms of new vessel formation for tissue regeneration. In vitro pre-vascularization is one of the leading scopes in the tissue-engineering field. Vascularization strategies that are associated with co-culture systems have proved that there is communication between different cell types with mutual beneficial effects in vascularization and tissue regeneration in two-dimensional or 3D cultures. Endothelial cells with different cell populations, including osteoblasts, smooth muscle cells, and fibroblasts in a co-culture have shown their ability to advocate pre-vascularization. In this review, a co-culture perspective of human gingival fibroblasts and vascular endothelial cells is discussed with the main focus on vascularization and future perspective of this model in regeneration and repair.
    Matched MeSH terms: Cell Culture Techniques
  9. Munirah S, Samsudin OC, Aminuddin BS, Ruszymah BH
    Tissue Cell, 2010 Oct;42(5):282-92.
    PMID: 20810142 DOI: 10.1016/j.tice.2010.07.002
    Monolayer culture expansion remains as a fundamental step to acquire sufficient number of cells for 3D constructs formation. It has been well-documented that cell expansion is however accompanied by cellular dedifferentiation. In order to promote cell growth and circumvent cellular dedifferentiation, we evaluated the effects of Transforming Growth Factor Beta-2 (TGF-β2), Insulin-like Growth Factor-I (IGF-I) and basic Fibroblast Growth Factor (bFGF) combination on articular chondrocytes culture and 'chondrocytes-fibrin' construct formation. Chondrocytes were serially cultured in: (1) F12:DMEM+10% Foetal Bovine Serum (FBS) with growth factors (FD10GFs), (2) F12:DMEM+2%FBS with the growth factors (FD2GFs) and, (3) F12:DMEM+10%FBS without growth factors (FD) as control. Cultured chondrocytes were evaluated by means of growth kinetics parameters, cell cycle analysis, quantitative phenotypic expression of collagen type II, aggrecan core protein sox-9 and collagen type I and, immunochemistry technique. Harvested chondrocytes were incorporated with plasma-derived fibrin and were polymerized to form the 3D constructs and implanted subcutaneously at the dorsum of athymic nude mice for eight (8) weeks. Resulted constructs were assigned for gross inspections and microscopic evaluation using standard histochemicals staining, immunochemistry technique and, quantitative phenotypic expression of cartilage markers to reassure cartilaginous tissue formation. Growth kinetics performance of chondrocytes cultured in three (3) types of culture media from the most to least was in the following order: FD10GFs>FD2GFs>FD. Following growth kinetics analysis, we decided to use FD10GFs and FD (control) for further evaluation and 'chondrocytes-fibrin' constructs formation. Chondrocytes cultured in FD10GFs preserved the normal diploid state (2c) with no evidence of aneuploidy, haploidy or tetraploidy. Expression of cartilage-specific markers namely collagen type II, aggrecan core protein and sox-9 were significantly higher in FD10GFs when compared to control. After implantation, 'chondrocytes-fibrin' constructs exhibited firm, white, smooth and glistening cartilage-like properties. FD10GFs constructs formed better quality cartilage-like tissue than FD constructs in term of overall cartilaginous tissue formation, cells organization and extracellular matrix distribution in the specimens. Cartilaginous tissue formation was confirmed by the presence of lacunae and cartilage-isolated cells embedded within basophilic ground substance. Presence of proteoglycan was confirmed by positive Safranin O staining. Collagen type II exhibited immunopositivity at the pericellular and inter-territorial matrix area. Chondrogenic properties of the construct were further confirmed by the expression of genes encoding collagen type II, aggrecan core protein and sox9. In conclusion, FD10GFs promotes the proliferation of chondrocytes and formation of good quality 'chondrocytes-fibrin' constructs which may have potential use of matrix-induced cell implantation.
    Matched MeSH terms: Cell Culture Techniques/methods
  10. Al Abbar A, Nordin N, Ghazalli N, Abdullah S
    Tissue Cell, 2018 Dec;55:13-24.
    PMID: 30503056 DOI: 10.1016/j.tice.2018.09.004
    Induced pluripotent stem cells (iPSCs) have great potentials for regenerative medicine. However, serious concerns such as the use of the viral-mediated reprogramming strategies and exposure of iPSCs to animal products from feeder cells and serum-containing medium have restricted the application of iPSCs in the clinics. Therefore, the generation of iPSCs with minimal viral integrations and in non-animal sourced and serum-free medium is necessary. In this report, a polycistronic lentiviral vector carrying Yamanaka's factors was used to reprogram mouse fibroblasts into iPSCs in feeder- and xeno-free culture environment. The generated iPSCs exhibited morphology and self-renewal properties of embryonic stem cells (ESCs), expression of specific pluripotent markers, and potentials to differentiate into the three-major distinct specialized germ layers in vitro. The iPSCs were also shown to have the potential to differentiate into neural precursor and neurons in culture, with greater than 95% expression of nestin, Pax6 and βIII-tubulin. This body of work describes an alternative method of generating iPSCs by using polycistronic lentiviral vector that may minimize the risks associated with viral vector-mediated reprogramming and animal derived products in the culture media.
    Matched MeSH terms: Cell Culture Techniques*
  11. Abdul Hamid Z, Lin Lin WH, Abdalla BJ, Bee Yuen O, Latif ES, Mohamed J, et al.
    ScientificWorldJournal, 2014;2014:258192.
    PMID: 25405216 DOI: 10.1155/2014/258192
    Hematopoietic stem cells- (HSCs-) based therapy requires ex vivo expansion of HSCs prior to therapeutic use. However, ex vivo culture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role of Hibiscus sabdariffa L. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0-1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival (P < 0.05) of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1(+) cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased (P < 0.05) the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs.
    Matched MeSH terms: Cell Culture Techniques/methods*
  12. Yaacob JS, Mahmad N, Mat Taha R, Mohamed N, Mad Yussof AI, Saleh A
    ScientificWorldJournal, 2014;2014:262710.
    PMID: 24977187 DOI: 10.1155/2014/262710
    Various explants (stem, leaf, and root) of Citrus assamensis were cultured on MS media supplemented with various combinations and concentrations (0.5-2.0 mg L(-1)) of NAA and BAP. Optimum shoot and root regeneration were obtained from stem cultures supplemented with 1.5 mg L(-1) NAA and 2.0 mg L(-1) BAP, respectively. Explant type affects the success of tissue culture of this species, whereby stem explants were observed to be the most responsive. Addition of 30 gL(-1) sucrose and pH of 5.8 was most optimum for in vitro regeneration of this species. Photoperiod of 16 hours of light and 8 hours of darkness was most optimum for shoot regeneration, but photoperiod of 24 hours of darkness was beneficial for production of callus. The morphology (macro and micro) and anatomy of in vivo and in vitro/ex vitro Citrus assamensis were also observed to elucidate any irregularities (or somaclonal variation) that may arise due to tissue culture protocols. Several minor micromorphological and anatomical differences were observed, possibly due to stress of tissue culture, but in vitro plantlets are expected to revert back to normal phenotype following full adaptation to the natural environment.
    Matched MeSH terms: Cell Culture Techniques/methods*
  13. Ibrahim AM, Kayat FB, Hussin ZE, Susanto D, Ariffulah M
    ScientificWorldJournal, 2014;2014:284342.
    PMID: 24757416 DOI: 10.1155/2014/284342
    Kenaf (Hibiscus cannabinus L.) is one of the important species of Hibiscus cultivated for fiber. Availability of homozygous parent lines is prerequisite to the use of the heterosis effect reproducible in hybrid breeding. The production of haploid plants by anther culture followed by chromosome doubling can be achieved in short period compared with inbred lines by conventional method that requires self pollination of parent material. In this research, the effects of the microspore developmental stage, time of flower collection, various pretreatments, different combinations of hormones, and culture condition on anther culture of KB6 variety of Kenaf were studied. Young flower buds with immature anthers at the appropriate stage of microspore development were sterilized and the anthers were carefully dissected from the flower buds and subjected to various pretreatments and different combinations of hormones like NAA, 2,4-D, Kinetin, BAP, and TDZ to induce callus. The best microspore development stage of the flower buds was about 6-8 mm long collected 1-2 weeks after flower initiation. At that stage, the microspores were at the uninucleate stage which was suitable for culture. The best callus induction frequency was 90% in the optimized semisolid MS medium fortified with 3.0 mg/L BAP + 3.0 mg/L NAA.
    Matched MeSH terms: Cell Culture Techniques/methods
  14. Alshelmani MI, Loh TC, Foo HL, Lau WH, Sazili AQ
    ScientificWorldJournal, 2013;2013:689235.
    PMID: 24319380 DOI: 10.1155/2013/689235
    Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF) of palm kernel cake (PKC). The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30°C and agitated at 200 rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w) on different PKC concentration-to-moisture ratios: 1 : 0.2, 1 : 0.3, 1 : 0.4, and 1 : 0.5. Results showed that Bacillus amyloliquefaciens 1067 DSMZ, Bacillus megaterium 9885 ATCC, Paenibacillus curdlanolyticus 10248 DSMZ, and Paenibacillus polymyxa 842 ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC-to-moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC.
    Matched MeSH terms: Cell Culture Techniques/methods
  15. Haque N, Rahman MT, Abu Kasim NH, Alabsi AM
    ScientificWorldJournal, 2013;2013:632972.
    PMID: 24068884 DOI: 10.1155/2013/632972
    Cell-based regenerative therapies, based on in vitro propagation of stem cells, offer tremendous hope to many individuals suffering from degenerative diseases that were previously deemed untreatable. Due to the self-renewal capacity, multilineage potential, and immunosuppressive property, mesenchymal stem cells (MSCs) are considered as an attractive source of stem cells for regenerative therapies. However, poor growth kinetics, early senescence, and genetic instability during in vitro expansion and poor engraftment after transplantation are considered to be among the major disadvantages of MSC-based regenerative therapies. A number of complex inter- and intracellular interactive signaling systems control growth, multiplication, and differentiation of MSCs in their niche. Common laboratory conditions for stem cell culture involve ambient O₂ concentration (20%) in contrast to their niche where they usually reside in 2-9% O₂. Notably, O₂ plays an important role in maintaining stem cell fate in terms of proliferation and differentiation, by regulating hypoxia-inducible factor-1 (HIF-1) mediated expression of different genes. This paper aims to describe and compare the role of normoxia (20% O₂) and hypoxia (2-9% O₂) on the biology of MSCs. Finally it is concluded that a hypoxic environment can greatly improve growth kinetics, genetic stability, and expression of chemokine receptors during in vitro expansion and eventually can increase efficiency of MSC-based regenerative therapies.
    Matched MeSH terms: Cell Culture Techniques
  16. Mohamed MS, Tan JS, Mohamad R, Mokhtar MN, Ariff AB
    ScientificWorldJournal, 2013;2013:948940.
    PMID: 24109209 DOI: 10.1155/2013/948940
    Mixotrophic metabolism was evaluated as an option to augment the growth and lipid production of marine microalga Tetraselmis sp. FTC 209. In this study, a five-level three-factor central composite design (CCD) was implemented in order to enrich the W-30 algal growth medium. Response surface methodology (RSM) was employed to model the effect of three medium variables, that is, glucose (organic C source), NaNO3 (primary N source), and yeast extract (supplementary N, amino acids, and vitamins) on biomass concentration, X(max), and lipid yield, P(max)/X(max). RSM capability was also weighed against an artificial neural network (ANN) approach for predicting a composition that would result in maximum lipid productivity, Pr(lipid). A quadratic regression from RSM and a Levenberg-Marquardt trained ANN network composed of 10 hidden neurons eventually produced comparable results, albeit ANN formulation was observed to yield higher values of response outputs. Finalized glucose (24.05 g/L), NaNO3 (4.70 g/L), and yeast extract (0.93 g/L) concentration, affected an increase of X(max) to 12.38 g/L and lipid a accumulation of 195.77 mg/g dcw. This contributed to a lipid productivity of 173.11 mg/L per day in the course of two-week cultivation.
    Matched MeSH terms: Cell Culture Techniques
  17. Zulkeflee Z, Aris AZ, Shamsuddin ZH, Yusoff MK
    ScientificWorldJournal, 2012;2012:495659.
    PMID: 22997497
    A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na⁺, Ca²⁺, and Mg²⁺, while Fe²⁺ and Al³⁺ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher pH would inhibit flocculation. Low dosage requirements were needed for both the cation and bioflocculant, with only an input of 50 mL/L for 0.1% (w/v) CaCl₂ and 5 mL/L for culture broth, respectively. These results are comparable to other bioflocculants produced by various microorganisms with higher dosage requirements.
    Matched MeSH terms: Batch Cell Culture Techniques/methods; Batch Cell Culture Techniques/standards*
  18. Tay ST, Rohani MY, Ho TM, Devi S
    PMID: 12757225
    Isolation of rickettsiae from patients' blood samples and organ samples of wild rodents from areas with high seroprevalence of rickettsial infections was attempted using cell culture assay and animal passages. L929 mouse fibroblast cells grown in 24 well tissue culture plate were inoculated with buffy coat of febrile patients and examined for the growth of rickettsiae by Giemsa, Gimenez staining and direct immunofluorescence assay. No rickettsiae were isolated from 48 patients' blood samples. No symptomatic infections were noted in mice or guinea pigs infected with 50 organ samples of wild rodents. There was no rickettsial DNA amplified from these samples using various PCR detection systems for Orientia tsutsugamushi, typhus and spotted fever group rickettsiae.
    Matched MeSH terms: Cell Culture Techniques
  19. Ahmad R, Ismail A, Saat Z, Lim LH
    PMID: 9322296
    Mosquito adults and larvae were collected from dengue high risk areas and transported to the laboratory for identification. Identified mosquitos were pooled according to the species, date and locality and stored at -70 degrees C. A total of 1,385 pools of Aedes albopictus and 267 pools of Ae. Aegypti were collected from major towns in 12 states in Peninsular Malaysia. Virus isolation was carried out using cell culture (C6/36 clone) of Ae. albopictus and detection of dengue virus by the peroxidase anti-peroxidase staining. All positive isolations were further re-confirmed by the reverse transcriptase-polymerase chain reaction (RT-PCR). Most of the pools were negative with PAP staining and RT-PCR. However, 11 mosquito pools were positive with PAP staining. On the other hand, samples from Terengganu, Pulau Pinang and Johor were positive using both methods.
    Matched MeSH terms: Cell Culture Techniques
  20. Tong CK, Seow HF, Ramasamy R
    Med J Malaysia, 2008 Jul;63 Suppl A:77-8.
    PMID: 19024992
    The immune modulatory properties of mesenchymal stem cell (MSC) had brought a new insight in cell-based neotherapy. However, recent works of MSC are focused exclusively on bone marrow-derived MSC. We evaluated the immunogenicity of cord blood-derived MSC (CB-MSC) on T lymphocytes. Human peripheral blood mononuclear cells (PBMC) were prepared by density gradient separation and culture with the presence or absence of CB-MSC. PBMC were collected for activation analysis by flow cytometry at 24-, 48-, and 72- hours. The results showed that, CB-MSC does not stimulate nor inhibit T lymphocyte activation.
    Matched MeSH terms: Cell Culture Techniques
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