human cancer assay the mda mb 435 human breast carcinoma cell line was isolated originally from pleural effusion of a patient with breast carcinoma and was found to be highly metastatic from the mammary fat pad m f p tumors as well as after i v injection in nude mice the txm 13 human melanoma cell line were originally isolated from brain metastases and were established from surgical specimens from melanoma patients at the university of texas m d anderson cancer center houston tex txm 13 human melanoma cell line was found to be highly tumorigenic and metastatic in nude mice the metastatic and tumorigenic properties of human melanoma and breast carcinoma cell lines in nude mice were found to correspond well with their colony forming efficiency in dense agarose hence the tests were carried on agarose the tumor cells were maintained in tissue culture in minimum essential medium mem supplemented with 5 or 10 fetal bovine serum fbs sodium pyruvate nonessential amino acids l glutamine and 2 fold vitamin solution gibco grand island n y the cultures were maintained on plastic and incubated in 5 co 2 95 air at 37 u00b0 c in a humidified incubator all cultures were free of mycoplasma and the following murine viruses reovirus type 3 pneumonia virus k virus theiler 39 s encephalitis virus sendai virus minute virus mouse adenovirus mouse hepatitis virus lymphocytic choriomeningitis virus ectromelia virus lactate dehydrogenase virus.