Digoxigenin

( 3β, 5β, 12β ) - -3,12,14 Trihydroxycard -20 ( 22) - enolide

Fixed

222 ° C.

Slightly soluble in water (403 mg · l-1 at 25 ° C)

Risk

3.545 mg · kg -1 ( LD50, guinea pigs, i.v.)

Digoxigenin ( DIG short ) is a cardenolide ( steroid) from the leaves of the foxglove Digitalis purpurea and woolly foxglove, Digitalis lanata. It is the aglycone of the cardiac glycoside digoxin.

Use

Digoxigenin is used in molecular biology for labeling of DNA and RNA. RNA probes in DIG is usually to uridine triphosphate (UTP ) are coupled, as it is specific for the RNA, wherein the DNA probes to deoxyuridine triphosphate ( dUTP ). The detection is carried out by an anti -digoxigenin antibody coupled to a reporter enzyme, which in turn causes a color reaction. Digoxigenin is detected only in the bound state ( hapten), so that this method is very well suited for the visualization of DNA ( for example, in Southern blotting ) or RNA ( for example in Northern blot or in situ, ie in the tissue). Under the force spectroscopy using an atomic force microscope, an optical or magnetic tweezers digoxigenin is used for anchoring the DNA molecules. Likewise, the specific binding is used to an anti -digoxigenin antibody.