Renografin density gradients

Weiss, E., Coolbaugh, J. C., and Williams, J. C. (1975) Separation of viable Rickettsia typhi from yolk sac and L cell host components by renografin density gradient centrifugation. Appl. Microbiol. 30, 456-463. 

Fig. 5. Renografin density gradient profile of dopamine. Vacuole isolation was performed as described in Fig. 4 with pectin-ase from Aspergillus niger in the cell digestion medium. Gradient fractions were analyzed for dopamine content as described in Fig. 1...

Fig. 6. Distribution of sanguin-arine, thebaine and Ot mannosi-dase on renografin density gradients after limited cell wall hydrolysis. Cell fractionation was carried out as described in Fig. 4 except pectinase was omitted from the digestion medium. The volume of fraction collected is reflected in the width of the bars in the graph. (A) San-guinarine and (B) thebaine content and (C) a-mannosidase activity were determined as described in Fig. 4. Data shown are from the same experiment. In the original protoplasts, the concentrations of sanguinarine and thebaine were 11.6 and 0.013 Mg mg protein, respectively...

The largest amount of dopamine was detected in the supernatant with the next highest concentrations in the low density region of the gradient (Fig. 5). Some dopamine was also present in the 8/16% renografin interface which upon electron microscopic inspection appeared to contain laticifer cells. These results are consistent with the data obtained by sucrose density gradient centrifugation (Fig. 3). 

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