title: Simple method for quantifying pulmonary metastases in a murine fibrosarcoma.
abstract: A simple method is described for quantitating pulmonary metastases in C57BL/6J mice implanted with the Lewis T241 fibrosarcoma. Lungs were removed from tumor-bearing mice, homogenized, and diluted to 14 ml with supplemented Roswell Park Memorial Institute Tissue Culture Medium 1640 (+5% fetal calf serum). Twenty-five microliters of lung suspension from individual mice were added to a flat-bottomed microtiter plate containing 175 microliters of supplemented media, pulsed with [3H]thymidine, and incubated for 20 hr at 37 degrees. The cells were processed with a multiple automated sample harvester and counted in a liquid scintillator. Total lung burden was extrapolated from measured radioactivity (as cpm) through the use of a standard curve. This method is reasonably accurate and precise and provides more quantitative information on the pulmonary metastatic process than most conventional assays.
mesh_terms: D000818:Animals; D004261:DNA Replication; D005354:Fibrosarcoma / Q000473:pathology* / Q000503:physiopathology; D008175:Lung Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000556:secondary*; D051379:Mice; D008810:Mice, Inbred C57BL