This depends on your experimental application. To starve for serum and growth factors - e.g. in starvation experiments prior to cell stimulation - use Media Minus Serum without supplemental growth factors (kit 4Z3-500-S). To starve for growth factors, use Complete Classic Medium without supplemental growth factors, 4Z0-500-S, which still contains 10% bovine serum. Our Serum-Free Media without growth factors (SF-4Z0-500-S) is a chemically defined, complete media that supports cell growth even though it lacks serum; it may be appropriate for certain starvation assays depending on your particular experimental set-up.