title: Production of transferrin by human cell lines in a defined protein-free system: detection by ELISA.
abstract: A double sandwich enzyme immunoassay using a combination of two polyclonal and one monoclonal antibodies was developed to quantitate transferrin in various human cell lines (U 937, K 562, Jiyoye, Jurkat, Raji, THP-1, HeLa) and transferrin secreted by these cells cultured in a defined protein-free medium. In the developed assay the measurable range in our experimental system is 1 to 25 ng/mL of human transferrin and the interassay coefficient of variation ranged from 11.3 to 16.1%. The assay is specific for both transferrin and apotransferrin with the same sensitivity. Intracellular transferrin levels in all the cell lines tested were < 1 ng/10(6) cells. The highest level of transferrin was found in cells of the histiocytic line U 937 (0.84 +/- 0.18 ng/10(6) cells). Only this cell line secreted transferrin in amounts > 1 ng/10(6) cells per day, i.e. 15.8 +/- 2.3 ng/10(6) cells per day. Intracellular transferrin was also demonstrated by immunoblotting.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of Czech Republic, Prague.
authors.forename: K
authors.initials: K
authors.lastname: Kriegerbecková
authors.forename: J
authors.initials: J
authors.lastname: Kovár
authors.forename: V
authors.initials: V
authors.lastname: Neumannová
mesh_terms: D002460:Cell Line; D016895:Culture Media, Serum-Free; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D014168:Transferrin / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
chemical_list: D016895:Culture Media, Serum-Free; D014168:Transferrin