Figure 3. Growth index (GI), antibody yield in the biomass (µg FW-1),total amount of 14D9 in the culture medium (µg 14D9 per flask) and in the biomass (µg 14Dp per flask) in 22 days-old N. tabacum AcK₆ hairy root clone with the addition of gelatine (1.0, 5.0 and 9.0 g l^-1), and PVP (1.0, 1.5 and 2.0 g l^-1). Gelatine and PVP were added to 2 days-old cultures. As control AcK₆ hairy root without any addition was used. Each point represents the mean of three replicates ± SD.