02028nas a2200193   4500008004100000022001400041245008000055210006900135260007600204300001200280490000700292520133000299100001701629700001601646700002001662700002501682700001901707856010801726       2012                        eng d  a8756-793800aControlled release of nutrients to mammalian cells cultured in shake flasks0 aControlled release of nutrients to mammalian cells cultured in s  aCOMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USAbWILEY-BLACKWELLcJAN  a188-1950 v283 a<p>Though cell culture-based protein production processes are rarely carried out under batch mode of operation, cell line and initial process development operations are usually carried out in batch mode due to simplicity of operation in widely used scale down platforms like shake flasks. Nutrient feeding, if performed, is achieved by bolus addition of concentrated feed solution at different intervals, which leads to large transient increases in nutrient concentrations. One negative consequence is increased waste metabolite production. We have developed a hydrogel-based nutrient delivery system for continuous feeding of nutrients in scale down models like shake flasks without the need for manual feed additions or any additional infrastructure. Continuous delivery also enables maintaining nutrient concentrations at low levels, if desired. The authors demonstrate the use of these systems for continuous feeding of glucose and protein hydrolysate to a suspension Chinese Hamster Ovary (CHO) culture in a shake flask. Glucose feeding achieved using the glucose-loaded hydrogel resulted in a 23% higher integral viable cell density and an 89% lower lactate concentration at the end of the culture when compared with a bolus-feed of glucose. (c) 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012</p>1 aHegde, Swati1 aPant, Tejal1 aPradhan, Ketaki1 aBadiger, Manohar, V.1 aGadgil, Mugdha  uhttps://library.ncl.res.in/content/controlled-release-nutrients-mammalian-cells-cultured-shake-flasks-001730nas a2200241   4500008004100000022001400041245010200055210006900157260007400226300001200300490000700312520082700319653001601146653001301162653004101175653003401216653001701250653002101267653003301288100002001321700001901341856012801360       2012                        eng d  a0920-906900aEffect of addition of `carrier' DNA during transient protein expression in suspension CHO culture0 aEffect of addition of carrier DNA during transient protein expre  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcDEC  a613-6220 v643 a<p>Transient protein expression using polyethyleneimine as a transfection agent is useful for the rapid production of small amounts of recombinant proteins. It is known that an increase in extracellular DNA concentration during transfection can lead to a nonlinear increase in intracellular DNA concentration. We present an approach that hypothesizes that this nonlinearity can be used to decrease the amount of plasmid required for productive transfections. Through addition of non coding `carrier' DNA to increase total DNA concentration during transfection, we report a statistically significant increase in protein (IgG) expression per unit plasmid used for transfection. This approach could be useful to increase protein yields for large scale transfections under conditions where plasmid availability is limited.</p>10aCarrier DNA10aCell age10aDNA: polyethyleneimine particle size10aMedium equilibration with CO210apH excursion10aSalmon sperm DNA10aTransient protein expression1 aPradhan, Ketaki1 aGadgil, Mugdha  uhttps://library.ncl.res.in/content/effect-addition-carrier-dna-during-transient-protein-expression-suspension-cho-culture-001811nas a2200229   4500008004100000022001400041245009700055210006900152260006700221300001400288490000700302520091800309653003001227653003201257653003001289653004001319653004301359100002001402700001601422700001901438856012401457       2012                        eng d  a8756-793800aIn situ pH maintenance for mammalian cell cultures in shake flasks and tissue culture flasks0 aIn situ pH maintenance for mammalian cell cultures in shake flas  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcNOV  a1605-16100 v283 a<p>pH in animal cell cultures decreases due to production of metabolites like lactate. pH control via measurement and base addition is not easily possible in small-scale culture formats like tissue-culture flasks and shake flasks. A hydrogel-based system is reported for in situ pH maintenance without pH measurement in such formats, and is demonstrated to maintain pH between 6.8 and 7.2 for a suspension CHO cell line in CD CHO medium and between 7.3 and 7.5 for adherent A549 cells in DMEM:F12 containing 10% FBS. This system for pH maintenance, along with our previous report of hydrogels for controlled nutrient delivery in shake flasks can allow shake flasks to better mimic bioreactor-based fed batch operation for initial screening during cell line and process development for recombinant protein production in mammalian cells. (C) 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012</p>10ahigh throughput screening10apH control for cell culture10apH control in shake flask10apH control in tissue culture flasks10asmall scale platforms for cell culture1 aPradhan, Ketaki1 aPant, Tejal1 aGadgil, Mugdha  uhttps://library.ncl.res.in/content/situ-ph-maintenance-mammalian-cell-cultures-shake-flasks-and-tissue-culture-flasks-0