Kinetic studies of cellular metabolic activity, specific IgG production rate, IgG mRNA stability and accumulation during hybridoma batch culture.

During I.13.17. hybridoma batch cultivation, the levels of cytoplasmic mRNAs specifying immunoglobulin heavy (H) and light (L) chains peaked during the exponential phase and decreased significantly during the decline phase. This variation was found to parallel the rate of DNA synthesis and the total cytoplasmic RNA content. Moreover, we have investigated the possibility that the stability of H- and L-chain mRNAs could account for the observed difference in their levels throughout the batch culture. Using a transcription inhibitor (actinomycin D), we found that the differential accumulation of both mRNAs reflected transcript stability. However, at any growth stage of the culture, the specific monoclonal antibody production rate (pg IgG cell-1 h-1) was not reflected by the levels of H- or L-chain mRNAs, but could be partially correlated to the specific metabolic activity of the cells.