Digoxigenin

Digoxigenin
IUPAC name 3-[(3S,5R,8R,9S,10S,12R,13S,14S,17R)-3,12,14-trihydroxy-10,13-dimethyl-1,2,3,4,5,6,7,8,9,11,12,15,16,17-tetradecahydrocyclopenta[a]phenanthren-17-yl]-2H-furan-5-one
Identifiers
CAS number	1672-46-4 Y
PubChem	15478
ChemSpider	14728 Y
ChEBI	CHEBI:42098 Y
ChEMBL	CHEMBL1153 Y
Jmol-3D images	Image 1
SMILES O=C/1OCC(=C\1)\[C@@H]2[C@@]4([C@](O)(CC2)[C@@H]5CC[C@@H]3C[C@@H](O)CC[C@]3(C)[C@H]5C[C@H]4O)C
InChI InChI=1S/C23H34O5/c1-21-7-5-15(24)10-14(21)3-4-17-18(21)11-19(25)22(2)16(6-8-23(17,22)27)13-9-20(26)28-12-13/h9,14-19,24-25,27H,3-8,10-12H2,1-2H3/t14-,15+,16-,17-,18+,19-,21+,22+,23+/m1/s1 Y Key: SHIBSTMRCDJXLN-KCZCNTNESA-N Y InChI=1/C23H34O5/c1-21-7-5-15(24)10-14(21)3-4-17-18(21)11-19(25)22(2)16(6-8-23(17,22)27)13-9-20(26)28-12-13/h9,14-19,24-25,27H,3-8,10-12H2,1-2H3/t14-,15+,16-,17-,18+,19-,21+,22+,23+/m1/s1 Key: SHIBSTMRCDJXLN-KCZCNTNEBN
Properties
Molecular formula	C23H34O5
Molar mass	390.51 g/mol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Digoxigenin (DIG) is a steroid found exclusively in the flowers and leaves of the plants Digitalis purpurea, Digitalis orientalis and Digitalis lanata (foxgloves), where it is attached to sugars, to form the glycosides (eg. Lanatoside C).^[1]

Use in biotechnology

Digoxigenin is considered a hapten, a small molecule with high immunogenicity used in many molecular biology applications. Other popular haptens include DNP (dinitrophenol), biotin, and fluorescein. In general, antibodies generated against haptens have higher affinities for their targets than other antibodies, so haptens are conjugated to other biological molecules as all-purpose immuno-tags. This is because anti-hapten antibodies have high affinities and are readily available, while antibodies may not be commercially available for exotic biological targets.

Digoxigenin is a standard immunohistochemical marker for in situ hybridization.^[2][3] In this case it is conjugated to a single species of RNA nucleotide triphosphate (typically uridine), which is then incorporated into RNA (a "riboprobe") as it is synthesized by the cellular machinery. Later, the digoxigenin ("Dig") markers are detected with anti-digoxigenin antibodies, which may be labeled with dyes or enzymes (see ELISA) for visualization and detection. In a similar manner, digoxigenin may be conjugated to sugars to study glycosylation events in biological systems.

References

1. ^ Polya, G.; Biochemical targets of plant bioactive compounds. New York: CRC Press, 2003. 847p
2. ^ Eisel, D.; Grünewald-Janho, S. & Krushen, B. (Eds.) Dig Application Manual for Nonradioactive in situ hybridization. 3rded. Penzberg: Roche Diagnostics GmbH, 2002. 242p
3. ^ Hauptmann, G.; Gerster, T. (1994). "Two-color whole-mount in situ hybridization to vertebrate and Drosophila embryos". Trends Genet 10 (8): 266. doi:10.1016/0168-9525(90)90008-T. PMID 7940754. 

See also

• Immunostaining