CONTINUOUS HYBRIDOMA CULTURE IN A LOW-PROTEIN SERUM-FREE MEDIUM SUPPLEMENTED WITH LIPOSOMES

A homemade serum-free medium containing a low protein level under 0.1 g l(-1) has been proved to support long-term cultures of VO 208 hybrid oma cells successfully up to 50 days. The low protein level was achiev ed by supplying the lipids through liposomes containing cholesterol, o leic acid, L-alpha dipalmitoyl phosphatidylcholine, and bovine serum a lbumin. The influence of the liposome content in the feeding medium wa s studied in a continuous culture performed with step variations of th e liposomes level, from 7.5 to 30 mi l(-1). The cell density decreased at the highest liposomes content while it became higher with 7.5 or 1 2 ml l(-1) of liposomes. For each step variation appeared a transitory activation of the specific rates of nutrient consumption, metabolite production and antibody secretion, as well as a transitory decrease of the specific cell growth rate. The overall structure of the antibodie s was not affected during the culture.