Quantitative Spectrophotometric Papergram Assays I: Tubercidin

The paper chromatographic characteristics of the cytotoxic agent tubercidin in a number of solvents is reported. The technique for the production of bioautographs on Eagle's KB carcinoma cells is described. A study of the quantitation of tubercidin on KB cells and on papergrams by ultraviolet analysis was undertaken. Using the same chromatograms, ultraviolet analysis followed by bioautographic assay allowed the compilation of data which were statistically analyzed by the pairing technique. This indicated that the two methods were equivalent; however, the ultraviolet assay is the method of choice inasmuch as it requires only half the time required for the biological method.