Centrifugations
Mostrando 1-12 de 48 artigos, teses e dissertações.
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1. AVALIAÇÃO DE SETE PROTOCOLOS DE OBTENÇÃO DE PLASMA RICO EM PLAQUETAS / EVALUATION OF SEVEN PROTOCOLS FOR PLATELET- RICH PLASMA (PRP) PROCESSING
O plasma rico em plaquetas (PRP) é obtido a partir do sangue total, através de uma ou duas centrifugações, resultando em um pequeno volume de plasma com elevado número de plaquetas contendo fatores de crescimento. O objetivo do presente estudo foi avaliar diferentes protocolos para obtenção de PRP através do método manual quanto à capacidade de con
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/02/2012
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2. Treonil-TRNA sintetase de germen de trigo : purificação e propriedades cineticas
Aminoacil - tRNA syntetases are enzymes that catalyse the first step of protein biosynthesis, the aminoacyl - tRNA formation. The substrates of the reaction are the L-aminoacid, ATP and tRNA, specific for this L-aminoacid. Magnesium ion parcipates as the cofactor of the reaction. The products of the reaction are aminoacyl - t.RNA, AMP and inorganic pyrophosp
Publicado em: 1991
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3. Propriedades cineticas da treonil-tRNA sintetase de figado bovino. Reações de intercambio ATP-PPi E de aminoacilação
Threonyl-tRNA synthetase was extracted from beef liver and purified by differential centrifugations, neutral salt precipitation and chromatographic procedures. The degree of purification obtained about 120 fold, with a yield of 7%. The analysis by polyacrylamide electrophoresis has shown a small heterogeneity at the last step of the enzyme purification. The
Publicado em: 1981
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4. Optimizing Culture of Chlamydia pneumoniae by Using Multiple Centrifugations
Three methods for the recovery of Chlamydia pneumoniae from spiked nasopharyngeal and blood specimens, including extended culture and additional centrifugations, were compared. Additional centrifugations and a 7-day culture time resulted in a 500- to 5,000-fold increase in the number of detectable inclusion-forming units.
American Society for Microbiology.
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5. Isolation and organization of calf ribosomal DNA.
Ribosomal DNA (rDNA) from calf was isolated by three density gradient centrifugations. The first centrifugation in Cs2S04/BAMD was used to obtain partially resolved dG+dC-rich fractions from total DNA. The second and third centrifugations, in Cs2S04/Ag+, led to the isolation of an rDNA fraction characterized by a symmetrical band in CsCl, p = 1.724 g/cm3. Th
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6. Isolation and properties of membranes from Bacillus megaterium spores.
Membranes from dormant and heat-activated spores of Bacillus megaterium QM B1551 were isolated and purified by gentle lysis procedures followed by differential and sucrose density gradient centrifugations. The purified membranes were enriched for inner membranes and were characterized by their density and content of proteins, phospholipids, enzymes, cytochro
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7. Extraction of rotavirus from human feces by treatment with lithium dodecyl sulfate.
A procedure has been developed for the isolation of rotavirus from human fecal specimens based on the resistance of the virus to treatment with cold 1% lithium dodecyl sulfate at neutral pH. A single detergent treatment of fecal material followed by low- and high-speed centrifugations yielded a virus suspension of sufficient purity for viral ribonucleic acid
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8. Detection of Pediococcus spp. in brewing yeast by a rapid immunoassay.
A membrane immunofluorescent-antibody test was developed to detect diacetyl-producing Pediococcus contaminants in brewery pitching yeast (yeast [Saccharomyces cerevisiae] slurry collected for reinoculation). Centrifugations at 11 and 5,100 x g separate yeast cells from bacteria and concentrate the bacteria, respectively. Pelleted bacteria resuspended and tra
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9. Simplified Method for the Production of Carbohydrate Antigen from Neisseria meningitidis1
The Gotschlich procedure for the production of carbohydrate antigens from the supernatant fluids of cultures of Neisseria meningitidis groups A and C was modified. Steps involving digestion with nucleases and gel filtration through Sephadex G-50 were added, the number of extractions was greatly reduced, and high-speed centrifugations were eliminated. The ant
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10. Sequential Sepharose chromatographic isolation of polysomes and polysomal RNAs depleted in nuclear RNA from Xenopus.
Analyses of sequence complexities, stage specific gene expression, and mRNA sequence divergence require polysomal RNA preparations relatively free of nuclear RNA contamination. Conventional procedures for the isolation of uncontaminated polysomal RNAs which rely on sucrose density centrifugations are laborious and unsuitable for large scale isolations. We de
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11. Antigens of Mycobacterial Cell Walls 1
Three antigenic fractions from the cell walls of eight strains of mycobacteria were studied. Isolation and purification of these antigens were effected by enzymatic digestions, differential and sucrose gradient centrifugations, dialyses, and column chromatography. Two of the fractions were termed cell wall tuberculins (CWT-1, solubilized with lipase; CWT-2,
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12. Synchronization of Somatic Embryogenesis in a Carrot Cell Suspension Culture
Synchronization of somatic embryogenesis was achieved in a carrot (Daucus carota L. cv. “Kurodagosun”) suspension culture by sieving the initial heterogeneous cell population, by density gradient centrifugation in Ficoll solutions, and by subsequent repeated centrifugations at a low speed (50g) for a short time (5 seconds), followed by transferring the c