Albino Swiss Mouse Embryo Fibroblasts (3T3 Line)
The 3T3 cell line is an important fibroblast culture, widely utilized in laboratory research, which was established from disaggregated tissue of an albino Swiss mouse (Mus musculus) embryo. Most 3T3 variants have been demonstrated to be negative for mousepox and for the polymerase reverse transcriptase, an indication of the absence of integral retrovirus genomes. When the 3T3 line was established in the early 1960s by George Todaro and Howard Green, the cells were considered somewhat of an anomaly. The majority of cell lines at that time induced tumors when they were injected into animal models, and it was generally accepted that for cells to be immortal, they must also be oncogenic. The fact that 3T3 cells could apparently grow indefinitely, while being unable to instigate tumor growth, helped scientists delineate for the first time the differences between cell mortality and a cell's ability to undergo oncogenic transformation.