Massive Fluid-Suspension Cultures of Certain Mammalian Tissue Cells. I. General Characteristics of Growth and Trends of Population23

Abstract

Studies on the growth of mammalian cells in fluid-suspension cultures under conditions of continuous aeration and agitation were continued, and additional strains of cells were grown successfully. The manner of growth in fluid-suspension cultures appeared to be a specific characteristic of the cell strains studied and ranged from single cell suspensions (NCTC clones 929 and 1469) to rather large compact aggregates (NCTC strains 1769 and 1985). Noncellular debris nearly always formed in fluid-suspension cultures of human skin epithelium (NCTC strain 1769) regardless of culture condition, but seldom formed in cultures of strain L (NCTC clone 929) or in cultures of mouse liver cells (NCTC clone 1469), and then only when necrosis was present. Debris appeared to originate from the serum. Average generation time was usually 2 days or more in length. Cultures of strain 1769 had the longest average generation time, 5.0 days, while cultures of clone 929 and liver clone 1469 had generation times of 3.6 and 3.2 days, respectively. The shortest generation time shown by any of the cultures reported here was 2.25 days for a culture of skin strain 1769. Irregular growth curves characterized skin strain 1769 cultures, while smooth growth curves were typical of cultures of clones 929 and 1469. When subculturing was delayed until the logarithmic phase had ended, the parent culture was often so necrotic that recovery by the daughter culture into a logarithmic phase was slow and uncertain.