Surface IgG content of murine hybridomas: Direct evidence for variation of antibody secretion rates during the cell cycle.

Previous experiments have shown that population average surface lgG content is correlated with the specific antibody production rates of batch hybridoma cultures. Therefore, surface associated lgG content of single hybridoma cells might indicate antibody secretion rates of individual cells. Moreover, the surface lgG content should reflect the pattern of secretion rates during the cell cycle.

Stability of producer hybridoma cell lines after cell sorting: a case study.

Flow cytometry was used in combination with immunofluorescent staining for intracellular and surface-associated antibody contents to identify a significant non-producer cell fraction in a murine hybridoma cell line that had shown a decline in monoclonal antibody productivity with passaging. Viable producer cells stained for surface-associated antibody content were isolated by cell sorting on the basis of surface fluorescence intensity. The fraction of nonproducers was initially reduced from 85% to 20%.

Effect of lactic acid on the kinetics of growth and antibody production in a murine hybridoma: secretion patterns during the cell cycle.

The effects of elevated lactic acid concentration on the cell cycle kinetics of hybridoma cell growth and antibody production in batch culture were studied using conventional methods based on population-average data analysis and using flow cytometry based on single-cell data analysis. When 33 mM lactic acid was initially present, the true specific growth rate was reduced by 37% and the cell specific antibody production rate increased by a factor of 2.6 relative to a control culture with no additional lactic acid.

Cell cycle kinetics of the accumulation of heavy and light chain immunoglobulin proteins in a mouse hybridoma cell line.

Rates of accumulation of immunoglobulin proteins have been determined using flow cytometry and population balance equations for exponentially growing murine hybridoma cells in the individual G1, S and G2+M cell cycle phases. A producer cell line that secretes monoclonal antibodies, and a nonproducer clone that synthesizes only kappa-light chains were analyzed. The pattern for the kinetics of total intracellular antibody accumulation during the cell cycle is very similar to the previously described pattern for total protein accumulation (Kromenaker & Srienc 1991).

Cell-cycle-dependent protein accumulation by producer and nonproducer murine hybridoma cell lines: a population analysis.

Single-cell rates of accumulation of cellular protein have been determined as a function of total protein content using flow cytometry and population balance equations for exponentially growing murine hybridoma cells in the individual G(1), S(1) and G(2) + M cell cycle phases. A novel flow cytometric technique for the identification of hybridoma cells in mitosis was developed and implemented. The data were obtained from a producer cell line which synthesizes and secretes high levels of monoclonal antibodies, and from a nonproducer clone which does not synthesize and secrete substantial amounts of antibody.