title: Cytosol type electrolyte medium suitable for long term growth of human cells with very low membrane potential.
abstract: Culture media for mammalian cells contain electrolytes at concentrations that approximate those of the extracellular fluid (ECF). However, we observed that HeLa strain cells can grow in a cytosol type, serum-free, high amino acid medium (KN13) in which the concentrations of K+, Mg2+ and Pi were increased to about 10 times those in ECF by replacing NaCl. The Ca2+ concentration of KN13 is 10% of that in ECF. The additions of Mg2+ and Pi are essential to prevent the harmful effect of a high concentration of K+ in the medium. Even an increase in the K/Na ratio to 7 and 9 permitted growth for at least 2 weeks and 4 days, respectively. HeLaP3 cells adapted to KN13 (HeLaK cells) have proliferated (4 fold/week) for 4 years in this medium. The Na,K-ATPase of HeLaK cells was the alpha 1 isoform. HeLaK cells in KN13 medium have a lower membrane potential (-3.0 +/- 6.1 mV) than that of the original HeLaP3 cells in DM160 (-26 +/- 10 mV).
authors.affiliation: Department of Biochemistry, Jichi Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kagawa
authors.forename: T
authors.initials: T
authors.lastname: Takaoka
authors.forename: T
authors.initials: T
authors.lastname: Hamamoto
authors.forename: T
authors.initials: T
authors.lastname: Ohta
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002455:Cell Division; D002470:Cell Survival; D003470:Culture Media; D003600:Cytosol / Q000502:physiology*; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011309:Preservation, Biological; D012492:Salts; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics
chemical_list: D003470:Culture Media; D015345:Oligonucleotide Probes; D012492:Salts; D000254:Sodium-Potassium-Exchanging ATPase