Labeling an Oligonucleotide

Written by: The Midland Certified Reagent Company

The oligonucleotide undergoes a labeling process. Read below to find out the important components that are needed and understand their importance.
The process of labeling an oligonucelotide can be done either with radioactivity or chemiluminescent methods. A fluourescent label is ideally used during this process to highlight and emphasize whatever the laboratory worker needs to identify. This type of labeling combines three components: spacer, signaling moiety, and a reactive group.

Spacer

The spacer separates the DNA from the molecules and also has the ability to prevent or enhance hydrophilicty and hydrophobicity. The DNA can also utilize the spacer to modify itself and create a more flexible strand to work with, making the spacer one of the most important components during the early phases of the process.

Signaling Moiety

The signaling moiety is an enzyme that can be a different molecule depending on the type of label that is required. There are multiple types of signaling moieties ranging from enzymes to fluorescent molecules. These moieties work hand-in-hand with the dual-labeled probes to enhance the labeling process.

Reactive Group

The reactive group attaches the label to the oligonucleotide. It is the final stage of the labeling process and is also one of the most important. With the other components performing their jobs, the reactive groups need to accurately label the oligo in a way that there is no deletion or in congruencies.

A molecular beacon probe is also an essential component to the labeling process because of their ability to quantify the target DNA. Normally used in real-time PCR assays, these probes are a special class of their own.