Digoxigenin



Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea and Digitalis lanata.

Use in biotechnology
Its small size and relative ease with which it can be attached to biological molecules, along with the availability of antibodies in order to target it, makes it a useful tool in biochemistry. Along with fluorescein, it has become the standard immunohistochemical marker for in situ hybridisation. In this case it is conjugated to a single species of RNA nucleotide triphosphate (typically Uridine), which is then incorporated into the riboprobe as it is synthesised.

It may also be conjugated with sugars, allowing the incorporation of specific sugars into glycoproteins to be imaged in a similar way.