Progressive Changes of the Growth Characteristics of the Human Diploid Cells in Serial Cultivation in Vitro

Abstract

Serially cultivated human diploid cells became waning at the 30th transfer and extinct finally under the author's experimental conditions.
From the analysis of their growth rates with various inoculum sizes, it was indicated that the smaller the inoculum size of human diploid cells was, the earlier the decline of their growth rate appeared. It was noted that the change in the replicating potency of diploid cells is due to the intensification of some cell density dependent characteristics. The intensified character was not the cellular leakiness, but the decline of feeder action.