Flow of Labeled Blood in Small Cylindrical Tubes and Glass Bead Systems

The transport of T 1824 by blood has been studied in glass bead columns and small cylindrical tubes. Technical improvements include a method for transilluminating blood in tubes of less than 1 mm. radius, permitting the observation of the outflowing dye spear. Curves of dye concentration in samples collected at the outflow are expressed in terms of τ and F (τ). These variables represent, respectively, the fraction of system volume displaced and the fraction of dye collected per unit τ interval. Results for blood and for an aqueous perfusion medium were closely similar in both the tube and bead experiments. In the tube experiments fair agreement was obtained between theoretical and experimental curves, but data in the smaller tubes were more subject to turbulent disturbances which could not always be precisely controlled.