Now a days it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complimentary DNA in a clone of cells, followed by its detection using autoradiography because:

Step-by-step solution

During cancer detection, for the presence of the mutated gene by using the autoradiographic technique, the complementary gene does not bind to the mutated gene, and hence in the photographic film, the gene is not observed, because the probe will not have the complementarity with the mutated gene.