We describe an analysis of the population dynamics of recombinant cultures using a dimensionless time variable. In situations where information on the history or growth dynamics of the culture is desired directly in terms of generations, a dimensionless time domain analysis is preferred to the conventional real time analysis. The dimensionless time domain approach that has been developed in this study appears to be quite effective in obtaining such information. The usefulness of this approach in analysis of practical situations has also been illustrated. This approach is also expected to be particularly useful in investigating the growth dynamics of recombinant cell systems where the culture concentration is a function of the cell histories quantitated in terms of generations (e.g. cultures growing under auxotrophic selection pressure).