The viability of cells in the waste products of CO2-laser evaporation of Cloudman mouse melanomas.

The viability of cells present in waste products originating during CO2-laser evaporation of Cloudman S91 mouse melanomas was investigated. Cytologic smears showed mainly carbonized particles and thermally damaged cells but some morphologically intact cells as well. Viability was tested with the trypan blue test, by in vitro culture and intramuscular and intraperitoneal inoculations in syngeneic mice. No dye-excluding cells were found in the trypan blue test. Growth was noted neither in vitro nor in vivo in the 127 mice, intramuscularly or intraperitoneally injected with 10(5) x 10(5)/10 microliter smoke or debris particles, and killed four weeks after inoculation. Viable tumor cells, derived from a Cloudman melanoma cell line and added to the smoke and debris suspensions, remained viable. Thus, a toxic influence of smoke and debris particles in viable tumor cells, which would make the viability tests meaningless, was excluded. It is highly unlikely that viable tumor cells do occur in the waste products of CO2-laser tumor vaporization.