Enhancement of Human Prolactin Synthesis by Sodium Butyrate Addition to Serum-Free CHO Cell Culture

Table 3

Bioactivity of purified hPRL obtained from CHO cells treated or not with NaBu, determined via Nb2 or Ba/F3-LLP cells against the First International Standard for recombinant hPRL (WHO 97/714) with an activity of 57.2 ± 11.4 IU/mg.

IU/mg hPRLa
Cells	0 mM NaBu	1 mM NaBu
Nb2	50.88 ± 5.33	61.21 ± 4.66
Ba/F3-LLP	50.07 ± 5.64	71.47 ± 4.33

aValues are means ± SD of two independent assays, each run with intra-assay quadruplicates.