Serum concentration effects on the kinetics and metabolism of hela-s3 cell growth and cell adaptability for successful proliferation in serum free medium

Abstract

The effect of serum content of culture medium on the kinetics of cell growth and metabolism has been studied in HeLa S3 culture. Increasing the serum concentration from 5 to 15% in Ham’s F12 medium increased the total number of living cells by about 30%. Further increase in serum concentration resulted in significant reduction in viable cell number. Meanwhile, increasing serum concentration in culture medium from 5 to 20% shows positive effect on cell viability and increased it from 38 to 74% in 144 h cultivated cultures. On the other hand, both of glucose consumption and lactate production rates were increased by the increase of serum concentration in the range between 5 and 20%. Based on these data, cells grown in Ham’s F12 medium of 10% serum were used for adaptation to serum free medium (SFM). Successive adaptation of cells to complete SFM was done by cultivating cells in different passages with the increased fraction of SFM in the cultivation medium. The ratios between SM (Ham’s F12 supplemented with 10%) to SFM (SMIF-6) were (100:0; 75:25; 50:50; 25:75; 10:90; 0:100). For each medium, cells were cultivated in 2-3 short passages for only 72 h to keep the cells in all cultures in their mid-exponential phase. Based on this cultivation strategy, HeLa S3 cells were completely adapted to serum free medium in only 880 hours. Neither growth kinetics nor physiological characterization (based on the data of glucose consumption rate and lactate production rate) were changed during the cell adaptation to SFM.