Weinberg’s Lab,”used 3T3 mouse cell lineswas first looking for cells that lose contact inhibition (focus) that piled on top of each other (most didn’t)he caused a tumorthen isolated DNA from that tumor, extracted it, then cloned DNA that’s in there. 99.99% of sequence will be mouse, but 1 gene is human. Can identify human DNA and distinguish from mouse DNA by molecular marker (weinberg able to take DNA isolated from human carcinoma cell–>this is how Ras^D first identified oncogene found in this cancer line and was able to transfer 3T3 cells and make them tumoregenic)Could have also changed the selection you use. original carcinoma isolating RasD, losing contact inhibition was first they looked for…can go back to same tumor DNA, keep transfection, instead of losing contact inhibition
can try to grow cells w/o any growth factors. Going to discover oncogene responsible for being able to grow in absence of growth factor”