Abstract: It is an object of the present invention to allow a cell to produce a protein at a high level using a medium containing an enzymatic degradation product of fish meat or a fish meat extract. A method of culturing a cell comprising starting culturing in an initial medium and feeding at least once a feed medium to the initial medium during culturing, wherein at least one of the initial medium or the feed medium contains an enzymatic degradation product of fish meat or a fish meat extract added thereto. A method of producing a protein of interest using the above culture method.

Abstract: While a desired protein is prepared by culturing an animal cell that produces the protein to cause the protein to be produced, level of heterogeneity components of the protein is modulated by performing the culture at a normal culture temperature for a certain period and then continuing the culture at a culture temperature lowered to 25-35° C.

Abstract: It is an object of the present invention to allow a cell to produce a protein at a high level using a medium containing an enzymatic degradation product of fish meat or a fish meat extract. A method of culturing a cell comprising starting culturing in an initial medium and feeding at least once a feed medium to the initial medium during culturing, wherein at least one of the initial medium or the feed medium contains an enzymatic degradation product of fish meat or a fish meat extract added thereto. A method of producing a protein of interest using the above culture method.