Digitalis purpurea detect DNA or RNA. It can easily be attached to nucleotides by chemical modifications. DIG molecules are often linked to uridine nucleotides; DIG-labeled uridine (DIG-U) can then be incorporated into RNA probes via "in vitro" transcription. Once hybridisation occurs "in situ", RNA probes with the incorporated DIG-U can be detected with anti-DIG antibodies conjugated to alkaline phosphatase. To reveal the hybridised transcripts, alkaline phosphatase can be reacted with a chromogen to produce a coloured precipitate. The colours of the petals of the "Digitalis purpurea" are known to be determined by at least three genes that interact with each other. The
Radioactive contamination from the Rocky Flats Plant of substantial contamination from the 1957 plutonium fire until after the highly visible 1969 fire, when civilian monitoring teams confronted government officials with measurements made outside the plant of radioactive contamination suspected to be from the 1969 fire, which consumed hundreds of pounds of plutonium (850 kg). The 1969 fire raised public awareness of potential hazards posed by the plant and led to years of increasing citizen protests and demands for plant closure. Releases from previous years had not been reported publicly prior to the fire; airborne-become-groundborne radioactive contamination extending well beyond the Rocky Flats plant was not publicly reported