Stabilizing effect of reduced cultivation temperature on human x mouse hybridomas

Interspecies hybridomas, such as human X mouse hybrid cells, usually show a high degree of unstability for monoclonal antibody (mAb) production. We investigated growth and specific rate of mAb-production during a period of 52 days after recloning human-mouse hybridomas at cultivation temperatures of 37 degrees C and 32 degrees C respectively. The lower cultivation temperature stabilized the overall IgM-mAb-production rate (IgM/ml) over the total cultivation period. At 37 degrees C incubation temperature the overall IgM-mAb-production was reduced to 1/3 due to loss of heavy chain production. This is visible from an increase of the kappa/mu-chain ratio. At 32 degrees C incubation temperature the specific IgM-mAb-production rate (IgM/cell X time) was stabilized, whereas at 37 degrees C incubation temperature a decrease of 80% was observed.