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Culture Plates (culture + plate)
Kinds of Culture Plates Selected AbstractsMass Fabrication of Small Cell Spheroids by Using Micro-patterned Tissue Culture Plate,ADVANCED ENGINEERING MATERIALS, Issue 10 2009Akinari Iwasaki A newly designed micro-patterned chamber was utilized to fabricate cell spheroids with a constant size (<200,,m) and cell number. By applying cytochalasin D as a chemical to control cell adhesion and aggregation, thousands of aggregated cells were formed in each patterned chamber. Importantly, the formed cell spheroids were collected by a simple pipetting process without using proteinase. [source] Substrate adhesion affects contraction and mechanical properties of fibroblast populated collagen latticesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Meng-Yi Chen Abstract Fibroblasts can condense a hydrated collagen lattice to a tissue-like structure. The purpose of this study was to evaluate the effect of substrate adhesion on the contraction and mechanical properties of fibroblast populated collagen lattices. Bacteriological grade polystyrene (BGPS) plates and tissue culture polystyrene (TCPS) plates were used as substrates for incubation of fibroblast populated collagen lattices. Hydrophobicity of the polystyrene surfaces was measured by the static sessile contact angle method. Collagen lattice contraction was recorded for 2 weeks, after which the lattices were mechanically tested. The BGPS culture plate had a significantly larger contact angle and was more hydrophobic than the TCPS culture plate. Both hydrophobicity and peripheral detachment of the collagen gel significantly decreased the time lag before initiation of gel contraction and increased the strength of the fibroblast populated collagen lattices. Substrate adhesion affects the contractility and strength of cell seeded collagen gels. This information may be useful in developing tissue engineered tendons and ligaments. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008 [source] Characterization of ammonia-assimilating bacteria in a lagoon for wastewater from a paddock of dairy cattleANIMAL SCIENCE JOURNAL, Issue 1 2002Hiraku SASAKI ABSTRACT We investigated microorganisms that assimilated ammonia in lagoon treatment processes. Ammonia-assimilating microorganisms were detected by nitrogen-limited medium that contained ammonia as the sole nitrogen source. Numbers of ammonia-assimilating aerobes (log CFU/g) were 3.4, 4.8, 5.0, 4.8 and 5.0 (log CFU/mL) on the culture plate incubated at 4°C, 10°C, 15°C, 20°C and 25°C, respectively. Many isolates used ammonia in high rates when they were purely cultivated in nitrogen-limited medium added to sterilized lagoon extract. Many of them used ammonia even when they were cultivated in media containing viable microbial flora of the lagoon. Among them, enterobacteriaceae and Pseudomonas sp. were identified by analysis of 16S ribosomal DNA. [source] In vitro antimicrobial activity of several concentrations of sodium hypochlorite and chlorhexidine gluconate in the elimination of Enterococcus faecalisINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2001B. P. F. A. Gomes Abstract Aim The aim of this study was to assess, in vitro, the effectiveness of several concentrations of NaOCl (0.5%, 1%, 2.5%, 4% and 5.25%) and two forms of chlorhexidine gluconate (gel and liquid) in three concentrations (0.2%, 1% and 2%) in the elimination of E. faecalis. Methodology A broth dilution test using 24-well cell culture plates was performed and the time taken for the irrigants to kill bacterial cells was recorded. Isolated 24 h colonies of pure cultures of E. faecalis grown on 10% sheep blood plus Brain Heart Infusion (BHI) agar plates were suspended in sterile 0.85% NaCl solution. The cell suspension was adjusted spectrophotometrically to match the turbidity of a McFarland 0.5 scale. One mL of each tested substance was placed on the bottom of wells of 24-well cell culture plates (Corning, NY), including the control group (sterile saline). Six wells were used for each time period and irrigant concentration. Two mL of the bacterial suspension were ultrasonically mixed for 10 s with the irrigants and placed in contact with them for 10, 30, and 45 s; 1, 3, 5, 10, 20, and 30 min; and 1 and 2 h. After each period of time, 1 mL from each well was transferred to tubes containing 2 mL of freshly prepared BHI + neutralizers in order to prevent a residual action of the irrigants. All tubes were incubated at 37°C for 7 days. The tubes considered to have positive growth were those which presented medium turbidity during the incubation period. Data were analysed statistically by the Kruskal,Wallis test, with the level of significance set at P < 0.05. Results All irrigants were effective in killing E. faecalis, but at different times. Chlorhexidine in the liquid form at all concentrations tested (0.2%, 1% and 2%) and NaOCl (5.25%) were the most effective irrigants. However, the time required by 0.2% chlorhexidine liquid and 2% chlorhexidine gel to promote negative cultures was only 30 s and 1 min, respectively. Conclusions Even though all tested irrigants possessed antibacterial activity, the time required to eliminate E. faecalis depended on the concentration and type of irrigant used. [source] Hypoxia suppresses runx2 independent of modeled microgravityJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004Christopher Ontiveros Bone loss is a consequence of skeletal unloading as seen in bed rest and space flight. Unloading decreases oxygenation and osteoblast differentiation/function in bone. Previously we demonstrated that simulation of unloading in vitro, by culturing differentiating mouse osteoblasts in a horizontal rotating wall vessel (RWV), results in suppressed expression of runx2, a master transcriptional regulator of osteoblast differentiation. However, the RWV is able to reproduce in a controlled fashion at least two aspects of disuse that are directly linked, model microgravity and hypoxia. Hypoxia in the RWV is indicated by reduced medium oxygen tension and increased expression of GAPDH and VEGF. To uncouple the role of model microgravity from hypoxia in suppressed runx2 expression, we cultured osteoblasts under modeled microgravity (oxygenated, horizontal RWV rotation), hypoxia (vertical RWV rotation), or both conditions (horizontal RWV rotation). The expression, DNA binding activity and promoter activity of runx2, was suppressed under hypoxic but not normoxic modeled microgravity RWV conditions. Consistent with a role for hypoxia in suppression of runx2, direct exposure to hypoxia alone is sufficient to suppress runx2 expression in osteoblasts grown in standard tissue culture plates. Taken together, our findings indicate that hypoxia associated with skeletal unloading could be major suppressor of runx2 expression leading to suppressed osteoblast differentiation and bone formation. © 2004 Wiley-Liss, Inc. [source] A NEW LARVAL FISH BIOASSAY FOR TESTING THE PATHOGENICITY OF PFIESTERIA SPP. (DINOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 3 2003Vincent J. Lovko Water quality, microbial contamination, prior fish health, and variable results have been major impediments to identifying the cause and mechanism of fish mortality in standard aquarium-format Pfiesteria bioassays. Therefore, we developed a sensitive 96-h larval fish bioassay for assessing Pfiesteria spp. pathogenicity using six-well tissue culture plates and 7-day-old larval cyprinodontid fish. We used the assay to test pathogenicity of several clonal lines of Pfiesteria piscicida Steidinger and Burkholder and P. shumwayae Glasgow and Burkholder that had been cultured with algal prey for 2 to 36 months. The P. shumwayae cultures exhibited 80%,100% cumulative mortality in less than 96 h at initial zoospore densities of approximately 1000 cells·mL,1. No fish mortalities occurred with P. piscicida at identical densities or in controls. In a dose-response assay, we demonstrated a strong positive correlation between dinospore density and fish mortality in a highly pathogenic culture of P. shumwayae, generating a 96-h LD50 of 108 zoospores·mL,1. Additionally, we applied the assay to evaluate a 38-L P. shumwayae bioassay that was actively killing fish and compared results with those from exposures of juvenile tilapia (Oreochromis niloticus) in a 500-mL assay system. Water from the fish-killing 38-L assay was filtered and centrifuged to produce fractions dominated by dinoflagellates, bacteria, or presumed ichthyotoxin (cell-free fraction). After 96 h, the larval fish assay exhibited 50%,100% cumulative mortality only in fractions containing dinoflagellates, with no mortalities occurring in the other fractions. The 500-mL bioassay with tilapia produced inconsistent results and demonstrated no clear correlation between mortality and treatment. The new larval fish bioassay was demonstrated as a highly effective method to verify and evaluate dinoflagellate pathogenicity. [source] Raman spectroscopy for rapid discrimination of Staphylococcus epidermidis clones related to medical device-associated infectionsLASER PHYSICS LETTERS, Issue 6 2008O. Samek Abstract We report on the potential application of Raman spectroscopy for the fast typing of Staphylococcus epidermidis (S. epidermidis) strains related to medical device-associated infections. In this study bacterial colonies were directly probed on culture plates and Raman spectra were recorded from volumes containing approximately 10 bacteria. The spectra contain information on the molecular composition of the whole bacteria, such as fatty acids, carbohydrates, proteins and nucleic acids, DNA as well as RNA. We demonstrate the potential to discriminate different S. epidermidis clones, even after only short Raman exposure/collection times. (© 2008 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Polypyrrole Thin Films Formed by Admicellar Polymerization Support the Osteogenic Differentiation of Mesenchymal Stem CellsMACROMOLECULAR BIOSCIENCE, Issue 8 2004Harold Castano Abstract Summary: The objective of this study was to evaluate the attachment, proliferation, and differentiation of rat mesenchymal stem cells (MSC) toward the osteoblastic phenotype seeded on polypyrrole (PPy) thin films made by admicellar polymerization. Three different concentrations of pyrrole (Py) monomer (20, 35, and 50,×,10,3M) were used with the PPy films deposited on tissue culture polystyrene dishes (TCP). Regular TCP dishes and PPy polymerized on TCP by chemical polymerization without surfactant using 5,×,10,3M Py, were used as controls. Rat MSC were seeded on these surfaces and cultured for up to 20 d in osteogenic media. Surface topography was characterized by atomic force microscopy, X-ray photoelectron spectroscopy, and static contact angle. Cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium content were measured to evaluate the ability of MSC to adhere and differentiate on PPy-coated TCP. Increased monomer concentrations resulted in PPy films of increased thickness and surface roughness. PPy films generated by different monomer concentrations induced drastically different cellular events. A wide spectrum of cell attachment characteristics (from excellent cell attachment to the complete inability to adhere) were obtained by varying the monomer concentration from 20 m to 50,×,10,3M. In particular the 20,×,10,3M PPy thin films demonstrated superior induction of MSC osteogenicity, which was comparable to standard TCP dishes, unlike PPy films of similar thickness prepared by chemical polymerization without surfactant. Adhesion of mesenchymal stem cells on tissue culture plates (TCP) coated with polypyrrole thin films made by admicellar polymerization. [source] Sequential detergent fractionation of primary neurons for proteomics studiesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2008Simonetta Bernocco Dr. Abstract Proteomics studies employing primary neurons are difficult due to the neurons' characteristics. We have developed a detergent-based fractionation method which reduces complexity of the protein extracts, is sufficiently fast to allow differential proteomics analysis after treatments of neurons for short time periods, can be applied to small numbers of cells directly in culture plates, and allows differential extraction of proteins in a compartment-specific manner. The sequential use of detergent-containing buffers on neurons in culture plates yields four extracts enriched in cytosolic, membrane-bound or enclosed, nuclear, and cytoskeletal proteins. Fractionation of neurons was validated by comparison of the distribution of known subcellular marker proteins in the four extracts using Western blotting. Comparison of extracts by DIGE showed a clear difference in protein composition demonstrating significant variations with a fold change (FC) of at least 1.20 for 82% of the detected spots. Using proteins identified in these spots that could be assigned a subcellular localization based on descriptions in the Uniprot database, an extraction efficiency of 85% was calculated for cytosolic proteins in extract 1, 90% for membrane-bound and membrane-enclosed proteins in extract 2, 82% for nuclear proteins in extract 3 and 38% for cytoskeletal and RAFT proteins in extract 4. [source] Antibacterial Nitric Oxide-Releasing Polyester for the Coating of Blood-Contacting Artificial MaterialsARTIFICIAL ORGANS, Issue 7 2010Amedea B. Seabra Abstract The emergence of multidrug-resistant bacteria associated with blood-contacting artificial materials is a growing health problem, which demands new approaches in the field of biomaterials research. In this study, a poly(sulfhydrylated polyester) (PSPE) was synthesized by the polyesterification reaction of mercaptosuccinic acid with 3-mercapto-1,2-propanediol and blended with poly(methyl methacrylate) (PMMA) from solution, leading to solid PSPE/PMMA films, with three different PSPE : PMMMA mass ratios. These films were subsequently S-nitrosated through the immersion in acidified nitrite solution, yielding poly(nitrosated)polyester/PMMA (PNPE/PMMA) films. A polyurethane intravascular catheter coated with PNPE/PMMA was shown to release nitric oxide (NO) in phosphate buffered saline solution (pH 7.4) at 37°C at rates of 4.6 nmol/cm2/h in the first 6 h and 0.8 nmol/cm2/h in the next 12 h. When used to coat the bottom of culture plates, NO released from these films exerted a potent dose- and time-dependent antimicrobial activity against Staphylococcus aureus and a multidrug-resistant Pseudomonas aeruginosa strains. This antibacterial effect of PSPE/PMMA films opens a new perspective for the coating of blood-contacting artificial materials, for avoiding their colonization with highly resistant bacteria. [source] Coatings of Low-Density Lipoprotein and Synthetic Glycoconjugates as Substrata for HepatocytesARTIFICIAL ORGANS, Issue 6 2009Hirofumi Yura Abstract Asialoglycoprotein (ASGP) receptors expressed on rat hepatocytes interact with glycoproteins containing galactose or N-acetylgalactosamine residues at the nonreducing termini of oligosaccharide chains to mediate endocytosis, and cholesterol transport protein with apolipoprotein B (LDL, low-density lipoprotein) in plasma interacts with LDL receptors and heparinoids in the extracellular matrix. We developed novel techniques to prepare galactose- and LDL-immobilized culture plates, using galactose-tagged polystyrene (galactose-carrying polystyrene [GalCPS]: N-p-vinylbenzyl-O-,-D-galactopyranosyl-[1,4]-D-gluconamide) and poly(2-acrylamide-2-methyl-1-propanesulfonate) (PAPS), respectively. Hepatocytes adhered well to plates coated with either GalCPS or LDL, and therefore the GalCPS- and LDL-coated plates were examined as specific substrata for culturing hepatocytes. These cultures promoted the formation of three-dimensional, multicellular aggregates with regulation of excess proliferation of non-parenchymal cells. Furthermore, the LDL coating resulted in higher albumin synthesis and an identical level of lactate dehydrogenase (LDH) compared with cells cultured on collagen- and GalCPS-coated plates. Thus, the two culture systems described here, and especially the LDL-coated plates, have potential for the development of a hybrid artificial liver. [source] A novel microplate-based screening strategy to assess the cellulolytic potential of Trichoderma strainsBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2010Stefano Cianchetta Abstract Bioconversion of lignocellulosic biomass to fuel requires a hydrolysis step to obtain fermentable sugars, generally accomplished by fungal enzymes. An assorted library of cellulolytic microbial strains should facilitate the development of optimal enzyme cocktails specific for locally available feedstocks. Only a limited number of strains can be simultaneously assayed in screening based on large volume cultivation methods, as in shake flasks. This study describes a miniaturization strategy aimed at allowing parallel assessment of large numbers of fungal strains. Trichoderma strains were cultivated stationary on microcrystalline cellulose using flat bottom 24-well plates containing an agarized medium. Supernatants obtained by a rapid centrifugation step of the whole culture plates were evaluated for extracellular total cellulase activity, measured as filter paper activity, using a microplate-based assay. The results obtained were consistent with those observed in shake-flask experiments and more than 300 Trichoderma strains were accordingly characterized for cellulase production. Five strains, displaying on shake-flasks at least 80% of the activity shown by the hyper-cellulolytic mutant Trichoderma Rut-C30, were correctly recognized by the screening on 24-well plates, demonstrating the feasibility of this approach. Cellulase activity distribution for the entire Trichoderma collection is also reported. One strain (T. harzianum Ba8/86) displayed the closest profile to the reference strain Rut-C30 in time course experiments. The method is scalable and addresses a major bottleneck in screening programs, allowing small-scale parallel cultivation and rapid supernatant extraction. It can also be easily integrated with high-throughput enzyme assays and could be suitable for automation. Biotechnol. Bioeng. 2010;107: 461,468. © 2010 Wiley Periodicals, Inc. [source] Scalable production of adeno-associated virus type 2 vectors via suspension transfection,BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2006Joon Young Park Abstract Vectors derived from adeno-associated virus type 2 (AAV2) are promising gene delivery vehicles, but it is still challenging to get the large number of recombinant adeno-associated virus (rAAV) particles required for large animal and clinical studies. Current transfection technology requires adherent cultures of HEK 293 cells that can only be expanded by preparing multiple culture plates. A single large-scale suspension culture could replace these multiple culture preparations, but there is currently no effective co-transfection scheme for generating rAAV from cells in suspension culture. Here, we weaned HEK 293 cells to suspension culture using hydrogel-coated six-well culture plates and established an efficient transfection strategy suitable for these cells. Then the cultures were gradually scaled up. We used linear polyethylenimine (PEI) to mediate transfection and obtained high transfection efficiencies ranging from 54% to 99%, thereby allowing efficient generation of rAAV vectors. Up to 1013 rAAV particles and, more importantly, up to 1011 infectious particles were generated from a 2-L bioreactor culture. The suspension-transfection strategy of this study facilitates the homogeneous preparation of rAAV at a large scale, and holds further potential as the basis for establishing a manufacturing process in a larger bioreactor. © 2006 Wiley Periodicals, Inc. [source] Transfection of Cells Mediated by Biodegradable Polymer Materials with Surface-Bound PolyethyleneimineBIOTECHNOLOGY PROGRESS, Issue 2 2000Ji Zheng Poly(,-CBZ- L -lysine) can be mixed with biodegradable polymers such as poly(D,L -lactic- co -glycolic acid) or poly(L -lactic acid) and formed into films, foams, or microspheres. Surface amino groups may then be deprotected with acid or lithium/liquid ammonia. The amino groups serve as a method to modify the surface by attachment of other molecules. In the present experiments, we show that these polymer materials, as films or foams, may be surface modified by the attachment of polyethyleneimine (PEI). Plasmid DNA attached to the PEI can transfect cells plated on the surface over several days. Covalent atachment of PEI was required for transfection to be efficient. PEI was also attached to surface-bound collagen on cell culture plates and was shown to mediate transfection. [source] Collagen barrier membranes decrease osteoclastogenesis in murine bone marrow culturesCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2010Hermann Agis Abstract Objective: Collagen barrier membranes (CBM) are used for guided bone regeneration to support the process of graft consolidation. It remains, unknown however, whether CBM can affect the consolidation of bone grafts by controlling the differentiation of progenitor cells into bone-resorbing osteoclasts and bone-forming osteoblasts. Material and Methods: To gain an insight into the underlying mechanisms, we performed in vitro bone marrow cultures on CBM (Bio-Gide®) under conditions that favor osteoclastogenesis and osteoblastogenesis, respectively. Measures of osteoclastogenesis were based on the number of tartrate-resistant acid-phosphatase-positive (TRAP+) multinucleated cells. Resorption assays revealed the activity of mature osteoclasts. Osteoblastogenesis was determined by alkaline-phosphatase activity. Viability was investigated utilizing the MTT assay. Results: Cultivation of murine bone marrow on CBM reduced the number of TRAP+ multinucleated cells compared with cultures on tissue culture plates. Inhibition of osteoclastogenesis was observed on the porous and the dense CBM surfaces. The majority of TRAP+ cells were mononucleated and the decreased osteoclastogenesis was not due to changes in cell viability. Furthermore, CBM are inert regarding the resorptive activity of mature osteoclasts. Moreover, osteoblastogenesis was not reduced when bone marrow cells were grown on the surface of CBM. Conclusions: These in vitro findings demonstrate that CBM can reduce the formation but not the activity of multinucleated osteoclasts. Our data further reveal that the formation of osteogenic cells from their progenitors is not reduced by the CBM. Overall, our results suggest that the beneficial effects of CBM during graft consolidation may involve their direct impact on osteoclastogenesis. To cite this article: Agis H, Magdalenko M, Stögerer K, Watzek G, Gruber R. Collagen barrier membranes decrease osteoclastogenesis in murine bone marrow cultures. Clin. Oral Impl. Res. 21, 2010; 656,661. doi: 10.1111/j.1600-0501.2009.01888.x [source] | ||||||||||||||||