Increased monoclonal antibody ascites production in mice primed with Freund's incomplete adjuvant

The production of monoclonal antibodies is conveniently achieved by propagation of antibody-secreting hybridoma cells as ascites tumours in mice. With a view to improve production and minimise animal usage, the choice of primer (pristane or Freund's incomplete adjuvant (FIA] and the effect of sex of mouse (female vs. uncastrated male) upon antibody yields were compared. The volume of ascitic fluid harvested from 134 FIA-primed mice was 697 ml, which was significantly (P less than 0.02) greater than the 343 ml collected from 116 pristane-primed mice. Moreover, FIA-primed mice required tapping for only 11 days (90% in 7 days) compared to the 17 days needed for pristane-primed mice. While there was little difference between the mean IgG1 concentration (as determined by enzyme immunoassay) of both ascites pools (4.9 mg/ml compared to 4.6 mg/ml), the volume differences equated to yields of 25.5 mg/mouse and 13.5 mg/mouse respectively. The FIA-primed mice were also shown to produce on average more (P less than 0.02) ascites per day. There was no significant difference found between the yield of monoclonal antibodies obtained from either uncastrated males (22.1 mg/mouse) or females (23.1 mg/mouse). The use of FIA to prime mice for the in vivo production of monoclonal antibodies should improve the yield to over 20 mg/mouse, thereby reducing the number of mice required.