Popis: |
Gelatin sponges, preimplanted in nude mice for 10 days, were used for an improved assay for tumorigenicity of cultured cells. Cells inoculated through the skin into such sponges yielded tumors more rapidly and with greater frequency than with newly implanted sponges or into subcutaneous tissue. However, an unexpected loss of cells occurred in the first few days after implantation. This loss may be an important aspect of tumorigenicity assays of all kinds, and is readily studied with the sponge methods described. |