A mutagen (Latin, roughly change maker) is an agent that changes the genetic information (usually DNA) of an organism and thus increases the number of mutations above the natural background level. Mutagens can be chemical compounds or radiation.
There are several methods to detect how mutagenic an agent is:
... who began acting on Broadway in 1936.
He was typecast as the wasp-tongued, supercillious sophisticate. His most famous role is that of the cranky professor forced to ...