Advantages of the Digoxigenin (Dig) Label

Digoxigenin (Dig), a steroid isolated from the digitalis, is a small molecule compound with strong immunogenicity. digitalis is the only natural source of dig, so anti-dig antibodies do not bind to other biological substances. Therefore, it has obvious advantages as an affinity label in oligonucleotides.

Fig.1 Chemical structure of dig and its natural source, digitalis. (Wikipedia)

Similar to Biotin Labels, dig labels are non-radioactive labels that are commonly used as a preferred strategy in kinds of hybridization reactions (such as northern blotting, southern blotting, in situ hybridization, etc.). The experimental procedure is to hybridize dig-labeled oligonucleotides with the targets, and then bind the dig labels specifically with anti-dig antibodies linked with fluorescent groups or enzymes, which are used for subsequent detection and analysis. The results are visualized by chemiluminescence reactions.

Digoxigenin-based Oligonucleotide Modification Service at CD BioGlyco

CD BioGlyco provides different strategies for dig-based oligonucleotide modification. Depending on your requirements, we will attach the dig labeling to the 5' terminal, 3' terminal, or internal of the oligonucleotide.

Dig labels are generally inserted into the oligonucleotides in the form of NHS esters. The Oligonucleotide must Be Linked to an Amino Group before the dig group is added. The oligonucleotide is usually modified with an amino C6 linker, followed by the coupling of the active amino couple to the digoxigenin NHS ester to form an amide bond.

• 5'-Dig linker: First, the 5' end of the oligonucleotide is attached to an amino group, and then a dig NHS ester reacts with an amino linker to form a dig-modified oligonucleotide mediated by an amide bond.
• 3'-Dig linker: Similar to the addition of 5'-d linker, the 3'-dig modified oligonucleotide begins with a 5'-amino modified oligonucleotide. An amino C6 linker acting as a spacer reduces steric hindrance between two groups.
• Internal dig linker: Dig labeling is added inside the oligonucleotide by replacing dT in the oligonucleotide fragment with dig-modified dT. Even if only a limited number of oligonucleotide templates are available or the purity of the templates is unsatisfactory, dig labeling can be easily inserted into the oligonucleotide by PCR technique.

Fig.2 Chemical structures of 5'-dig linker, 3'-dig linker, and internal dig linker. (CD BioGlyco)

In order to improve the detection sensitivity and amplify the detection signal, CD BioGlyco recommends adding multiple dig labels to your oligonucleotides and spacing the two labels by about 10 bases to prevent spatial interactions between groups.

Applications

• Dig-labeled oligonucleotide probes.
• DNA-DNA hybridization.
• DNA-RNA hybridization.
• Dot blotting.
• Clonal hybridization.
• In situ hybridization.
• Enzyme immunoassay.

Highlights

• Mature oligo dig modification technology.
• Reliable expert team.
• Comprehensive technique platform.
• End-to-end pre-sales and after-sales service.

CD BioGlyco is a biotechnology company that provides bioscience products and custom services to scientists worldwide. Our Glyco™ Synthesis Platform has been recognized internationally. We look forward to deep cooperation with you. Please feel free to contact us experts for more information.