Using Oxygen Uptake Rates to Time Infections in The Baculovirus Expression Vector System

Abstract

In this article, the problem of optimising insect cell cultures infected with a recombinant Baculovirus is discussed. A model of the infection of insect cells in batch cultures suggests that the maximum achievable yield is very sensitive to the time of infection (TOI). The optimal TOI is a function of the multiplicity of infection (MOI). MOI itself, however, has little effect on the maximum achievable yield. The optimal time of infection was found to be during the early to mid-exponential phase of the culture. The specific oxygen uptake rate was found to be at its highest and to be relatively constant during this period. The proportionality between viable cell density and the volumetric oxygen uptake rate (vOUR) indicates that vOUR can be used as an online measurement of viable cell density enabling automatic infection. Furthermore, high yielding infections were characterised by a continued significant increase in volumetric oxygen uptake rate following infection. This indicates that vOUR also has potential as a diagnostic tool.