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
New Drug Application Review should complete within 6 months. The decision comes in a "Complete Response Letter". Biologics, such as vaccines and many recombinant proteins used in medical treatments are generally approved by FDA via a Biologic License Application (BLA), rather than an NDA. The manufacture of biologics is considered to differ fundamentally from that of less complex chemicals, requiring a somewhat different approval process. Generic drugs that have already been approved via an NDA submitted by another maker are approved via an Abbreviated New Drug Application (ANDA), which does not require all of the clinical trials normally required for a new drug