A method of labeling rat ascites tumor cells with diazotized sulfanilic-S35 acid is described. The distribution of radioactivity in host rats with labeled subcutaneous or ascites tumor implants was studied; radioactivity was found to be present mainly in the tumor, kidneys, spleen, liver, and blood, decreasing in specific activity in that order. In general, the tissue localization of the label derived from the labeled tumor cells in the host rat resembled the patterns observed by Haurowitz et al. (5) following injection of labeled sulfanil-azotyrosine and sulfanil-azoovalbumin and differed from the distribution of free sulfanilic-S35 acid administered intraperitoneally.
This work was aided by grants-in-aid from the American Cancer Society (P-205 and California Division Special Grant No. 203).