Growth medium utilization and its re-use for animal cell cultures

The re-use of culture supernatant fluid (CS) as medium for the growth of BHK and RPMI 8226 (human lymphocyte) cell lines was investigated. Results indicate that CS from batch, semi-continuous and continuous cultures could be utilized as growth medium following the addition of lactalbumin hydrolysate (LH), tryptose phosphate broth (TPB), glucose, glutamine and 1% serum (CS with these additives is called supplemented CS). The main sources of amino acids and peptides in fresh media and in supplemented CS were found to be LH and TPB. The growth rate and cell concentrations of both BHK and RPMI 8226 cell lines in the supplemented CS were similar to those in the fresh medium. The growth of Sindbis virus was found to be unaltered in BHK cells in supplemented CS, compared with results using fresh medium. A second re-use of CS was unsuccessful in both cell lines. The cost of the supplemented CS was 5-10% that of fresh medium.