Animal cells are important in producing several products, but anchorage-dependency of most cell strains is one of the difficulties to get over. Microcarrier was utilized in this study in order to increase the surface area for cell-anchorage and also to improve other characteristics of the cell culture system.
First the critical parameters affecting the initial attachment were determined. The best plating efficiency was found at pH=7.4 and 5% FCS concentration. Use of the intermittent stirring during the initial phase of cell culture gave better cell plating than the continous stirring.
Next the human fibroblast interferon was successfully produced from cells cultured on microcarrier and several advantages of using microcarrier were identified. Usually 10,000 units/ml of interferon was produced from microcarrier culture as compared to 6,000 units/ml in monolayer culture. FCS concentration in cell growth stage affected the yield of interferon and gave optimum results at 5%. Antibiotics did not influence the production of interferon significantly.
The highest sensitivity in interferon assay was obtained with Hep 2 cells as the target cells and more than 3×10⁵ cells/ml were needed for good result. Microcarrier culture fixed onto confluent monolayer showed results as good as suspension microcarrier culture.