A simple endpoint dilution method for evaluating serum used for cell culture

A simple endpoint dilution method for evaluating foetal calf serum quality is described. The test uses a series of doubling dilutions of cells on microtitre trays with the test sera added to replicate dilution series. After five to six days of incubation the cells are stained with crystal violet and the end points read macroscopically. The cell growth-promoting property of serum may be expressed as a reciprocal of the cell dilution resulting in an approximately 50% coverage of cells.