• KSBB Journal
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• v.7 no.2
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• pp.96-101
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• 1992

A low serum medium(LSM) suitable for the growth of a self-constructed hybridoma cell line, KA112, was established by selecting ingredients to replace serum. Insulin and sodium pyruvate was important for the growth of cell line KA112. Various basal media were tested and DMEM gave the most favorable result. Low serum medium (LSM) developed in this work showed cell line stability in the culture for more than 6 months and exhibited cell growth equivalent to that carried out in medium supplemented with 7% FBS. LSM was found to be applicable to the suspension culture of KA112. The reduction of serum level down to 1%(V/V) FBS in LSM resulted in a substantial saving in the cost of media preparation for large scale culture.

• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.141-151
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• 1992

Physiological changes of the murine hybridoma cell line $S3H5/\gamma{2bA2}$ during adaptation to RPMI 1640 medium with 1%(v/v) fetal bovine serum were characterized in terms of cell growth, antibody production, morphology, and metabolic quotients. Cells adapted to 1% serum medium in T-flasks became sensitive to shear induced by mechanical agitation and required at least 5% serum in the medium or spent medium for cell growth in spinner flasks, while cells adapted to 10% serum medium in T-flasks could grow in 1% serum medium in spinner flasks. Consequently, long-term adaptation to low serum media may not give the expected growth enhancement. After adaptation to 1% serum medium, changes in cell morphology were observed. The cells in 10% serum medium were uniform and circular, while cells in 1% medium were irregularly shaped. The DNA contents, which were measured by flow cytometry, were almost constant among the cells in the range of 1% to 10%. Further, no significant changes in energy metabolism and specific monoclonal antibody production rate were observed among these cells.

• Biomedical Science Letters
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• v.9 no.3
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• pp.111-121
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• 2003

Recombinant single chain Fv (scFv) antibodies offer many advantages over mouse monoclonal antibodies such as faster clearance from blood, improved tumor localization, reduced human anti-mouse antibody (HAMA) response, and the availability to manipulate the scFv through genetic approaches. The recombinant phage display was constructed using lym-l hybridoma cells as a source of genetic starting material. mRNA was isolated from the corresponding antibodies hybridoma cells. VH and VL cDNA were amplified with RT-PCR and linked with ScFv by linker DNA to form ScFv DNA, which then were inserted into phagemid pCANTAB5E. The phage of positive clones selected with tube containing raji lymphoma cell and infected by competent E. coli HB2151 to express soluble scFv. The scFv lym-l was secreted into the cytosol and culture supernatant and shown to be of expected size (approximately 32 kDa) by western blot. An active scFv lym-l could be produced in E. coli with soluble form and high yield from hybridoma cell line, using phage display system. Immunoreactivity indicated that scFv lym1 showed a potential biding affinity against the raji lymphoma cell as its parental antibody (intact lym-l Ab).

• KSBB Journal
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• v.8 no.1
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• pp.28-35
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• 1993

The serum free medium was developed and used for the suspension culture of mammalian cells. Although there were the problems of the longer lag time and the smaller maximum cell concentration achievable, the higher specific productivity as well as other advantages of the serum free medium can make it a more realistic alternative. The existence of a staggering period in glucose concentration vs. time profile in the batch culture can be a practical indicating signal for performing fed batch culture. The concentration dependence of the effects of the additives in the serum free medium as well as its economic feasibility was also tested.

• KSBB Journal
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• v.13 no.1
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• pp.108-113
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• 1998

The cell growth and amino acid metabolism of a hybridoma cell line in T-flasks, spinner flasks, and a 2L bioreactor were compared. Similar growth and metabolic behaviour were observed for spinner flask and bioreactor cultivations, while those in T-flasks differed significantly. Through a detailed analysis of nutrients and wastes, 7 amino acids were found to be consumed to a much higher extent than the rest of the amino acids. Supplementing the based medium with selected amino acids, glucose, and vitamines increased the cell density by 70%. The addition of vitamines was found to increase the metabolic rates of glucose and lactate.

• KSBB Journal
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• v.13 no.5
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• pp.585-592
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• 1998

The effect of intracellular Ca2+ level on the hybridoma cell growth and monoclonal antibody(MAb) production was examined. For the manipulation of intracellular Ca2+ concentration, the cells were treated with A23187, ryanodine, and thapsigargin at about 1x106 cells/mL. The treated cells were recultivated by using the Iscove's Modified Dulbecco's Medium(MDM) containing 1.49mM CaCl2. The ryanodine-treated cells showed better cell growth, MAb concentration, and specific MAb productivity than others. In comparison with control, the maximum cell concentration, MAb concentration, and specific MAb productivity were increased by 40.6%, 48.1% and 83.3%, respectively. Confocal microscopic images of Fura-2/AM loaded cells indicate that the increase in intracellular Ca2+ level can enhance the MAb productivity by allowing the calcium influx into the endoplasmic reticulumn.

• KSBB Journal
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• v.4 no.2
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• pp.143-149
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• 1989

A cell sedimentaion system was designed and employed for the high culture of hydridoma. An upward divering cell settler allowed a good sedimentation of hybridoma but the accumulation of cell mass on the settler's wall side was a potential prolem. Although a cyinderical cell settler was useful to solve this problem, this device was employable only at low dilytion rate. A modified cell settler could support the high density culture of hybridoma at a concentration of $5{\times}10^6$ cell/ ml during 1 week, producting 380mg of monclonal antibody.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.8-13
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• 1998

Animal cells in culture typically convert most of the glucose they consume into lactate. The accumulation of lactate, however, is commonly cited as one of the factors that inhibit cell growth and limit the maximum cell concentration that can be achieved in culture. The specific production of lactate and the amount of glucose converted to lactate can be reduced when cells are grown in a fed-batch culture in which the residual glucose concentration is maintained at low levels. Such a fed-batch culture was used to grow and adapt hybridoma cells into a low-lactate-producing state before changing into continuous culture. The cells reached and maintained a high viable cell concentration at steady state. In a similar manner, cells that were initially grown in batch culture and a glucose-rich environment reached a steady state with a cell concentration that is much lower. The feed composition and dilution rates for both cultures were similar, suggesting steady state multiplicity. From a processing perspective the desired steady state among those is the one with the least metabolite production. At such seady state nutrient concentration in the feed can be further increased to increase cell and product concentrations without causing the metabolite inhibitory effect typically seen in a cell culture. Controlling cell metabolism in a continuous culture to reduce or eliminate waste metabolite production may significantly improve the productivity of mammalian cell culture processes.

• KSBB Journal
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• v.7 no.2
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• pp.92-95
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• 1992

A model for the role of serum was proposed to develop a low serum medium for the large scale cu1ture of mammalian cell. The strategy of medium development adopted in this study facilitated the understanding of the role being carried out by the serum in the culture of hybridoma KAl12 cell line. In this model, the serum components were divided into two main groups : the first group encompasses the nutrient factors that determine the maximum cell density and the second group includes the growth factors that regulate the cell growth rate, The model prediction was compared with the experimental results. The model enabled us to find out several useful aspects of medium composition for cell growth. 1) One particular component in the basal medium became limiting factor when serum concentration level was more than 7%. 2) The growth regulating factors and nutrient factors limited the cell growth at 3% and 5% serum concentration levels respectively.

• KSBB Journal
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• v.14 no.2
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• pp.188-191
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• 1999

We have investigated the fortifying effect of amino acids on the cell growth and productivity during the perfusion culture of hybridoma vR8 cells in serum-free media. Through the quantitative analysis of amino acids and metabolites in perfusion culture, we found that many amino acids(glutamine, histidine, arginine, methionine, isoleucine, leucine, phenylalanine, tryptophane) were heavily consumed at cell density of $1.06{\times}10^7$cells/mL. Due to amino acid depletion, cells died suddenly. So we supplemented the media with those amino acids by 30-170%. As a result, were could increase maximum cell density by 270%, average specific productivity by 175%, and average volumetric productivity by 560% in this fortified media, GC-HY-S2.