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Start Over Coverage 517-526

2. Cell-tak coating interferes with DNA-based normalization of metabolic flux data

Creator:
Sima, Michal, Martinkova, Stanislava, Kafkova, Anezka, Pala, Jan, and Trnka, Jan
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
metabolic flux analysis, normalization, and Cell-Tak
Language:
English
Description:
Metabolic flux investigations of cells and tissue samples are a rapidly advancing tool in diverse research areas. Reliable methods of data normalization are crucial for an adequate interpretation of results and to avoid a misinterpretation of experiments and incorrect conclusions. The most common methods for metabolic flux data normalization are to cell number, DNA and protein. Data normalization may be affected by a variety of factors, such as density, healthy state, adherence efficiency, or proportional seeding of cells. The mussel-derived adhesive Cell-Tak is often used to immobilize poorly adherent cells. Here we demonstrate that this coating strongly affects the fluorescent detection of DNA leading to an incorrect and highly variable normalization of metabolic flux data. Protein assays are much less affected and cell counting can virtually completely remove the effect of the coating. Cell-Tak coating also affects cell shape in a cell line-specific manner and may change cellular metabolism. Based on these observations we recommend cell counting as a gold standard normalization method for Seahorse metabolic flux measurements with protein content as a reasonable alternative.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Effects of salt stress on photosynthesis, PSII photochemistry and thermal energy dissipation in leaves of two corn (Zea mays L.) varieties

Creator:
Hichem, H., El Naceur, A., and Mounir, D.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, photosynthesis, ion accumulation, salinity, and Zea mays L.
Language:
Multiple languages
Description:
The effect of four different NaCl concentrations (from 0 to 102 mM NaCl) on seedlings leaves of two corn (Zea mays L.) varieties (Aristo and Arper) was investigated through chlorophyll (Chl) a fluorescence parameters, photosynthesis, stomatal conductance, photosynthetic pigments concentration, tissue hydration and ionic accumulation. Salinity treatments showed a decrease in maximal efficiency of PSII photochemistry (Fv/Fm) in dark-adapted leaves. Moreover, the actual PSII efficiency (ϕPSII), photochemical quenching coefficient (qp), proportion of PSII centers effectively reoxidized, and the fraction of light used in PSII photochemistry (%P) were also dropped with increasing salinity in light-adapted leaves. Reductions in these parameters were greater in Aristo than in Arper. The tissue hydration decreased in salt-treated leaves as did the photosynthesis, stomatal conductance (g s) and photosynthetic pigments concentration essentially at 68 and 102 mM NaCl. In both varieties the reduction of photosynthesis was mainly due to stomatal closure and partially to PSII photoinhibition. The differences between the two varieties indicate that Aristo was more susceptible to salt-stress damage than Arper which revealed a moderate regulation of the leaf ionic accumulation. and H. Hichem, A. El Naceur, D. Mounir.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public