1,2‐Dibromoethane as an Initiating Agent for Cell Transformation

The two‐stage transformation assay increases the sensitivity of cells to chemicals and permits detection of carcinogens acting as initiating agents. 1,2‐Dibromoethane, a representative halogenated aliphatic, has been tested in the two‐stage BALB/c 3T3 cells transformation test at dosages from 16 μM to 128 μM. This dose range is much lower than those previously found efficient in transforming BALB/c 3T3 cells. Apart from the lowest dose, which induced borderline effects, all the other assayed dosages appeared to induce heritable changes in the traget cells. The initiated cells were revealed as fully transformed foci both in the combination with a chronic promoting treatment and also by allowing cells to perform more rounds of cell replication. The results clearly show that 1,2‐dibromo‐ethane can act as an initiator of cell transformation.