[A simple method of continuous passage of human tumors in immunocompetent mice]

A simple procedure is described for the continuous passage of a human tumor in immunocompetent mice. The BRO human melanoma was transplanted consecutively 25 times by implanting tumor tissue under the sub--renal capsule of mice which had been immunosuppressed by a single dose of whole--body irradiation or by cytosine arabinoside followed by irradiation. The tumor grew continuously for 14 days, and cytological examination showed that the growth consisted almost entirely of tumor cells.