Cell culture media preparation and curcuminoid solubilization in FCS produced by different mixing techniques. A) Solutions for cell culture media were prepared by adding either solid (white bars) or DMSO-dissolved (500 mM) curcuminoids (gray bars) to FCS. The FCS was subsequently added to DMEM at a final concentration of 5%. The total curcuminoid concentrations in the media were then determined by butanol extraction. The measured (meas.) values were compared to the calculated (calc.) values (brackets) for both media prepared with solid (white bars) and DMSO-dissolved (gray bars) curcuminoids. On the right side of the panel DMSO-dissolved (gray bars) or solid curcuminoids (white bars) were mixed with FCS either by stirring or by rotation. The total amount of total curcuminoids solubilized by either method was determined spectrophotometrically. B) Elution profiles after separation by reversed phase chromatography of DMSO-dissolved curcuminoids solubilized in FCS, mixed either by stirring (right) or rotation (left). C) Elution profiles of solid curcuminoids solubilized in FCS, mixed either by stirring (right) or rotation (left).