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Core Concepts
Scientific Fundamentals Explained


Oligonucleotides are hydrophilic and often have difficulty permeating cell membranes. Cholesterol is hydrophobic, and when conjugated to oligonucleotides, can facilitate uptake into cells. It has been used as a transfection aid for antisense oligos and siRNAs, both in vitro and in vivo. The TEG (15 atom triethylene glycol) spacer further increases cellular uptake.

Quick facts:

Availability: DNA and RNA

Location: 3'

Scales: 100 nmol to 10 𝝁mol

Purification: HPLC required

IDT Ordering Symbol: /3CholTEG/


Figure 1. Cholesterol-TEG. Cholesterol-TEG can be used to modify both DNA and RNA oligos on scales from 100 nmol to 10 μmol. Because cholesterol is difficult to manufacture, it requires HPLC purification. To order, use the symbol /3CholTEG/.

Additional reading

DNA Oligonucleotide Resuspension and Storage
Upon receiving newly synthesized oligonucleotides, researchers must decide how to resuspend and store the product. Here are some guidelines and recommendations.

Oligonucleotide Modifications: Choosing the Right Mod for Your Needs
Guidelines on selecting oligonucleotide modifications and a discussion of how they can help you in your research.

Oligo Modification—Post-Synthesis Conjugation Explained
A description of addition of NHS esters and of amino and alkene modifications through use of click chemistry. We also provide answers to common questions regarding post-synthesis conjugation.

Which Biotin Modification to Use?
A discussion of the applications for each of the different biotins available through IDT.

Author: Jeremy Pritchard is a Technical Support Representative at IDT.

© 2016, 2011 Integrated DNA Technologies. All rights reserved. Trademarks contained herein are the property of Integrated DNA Technologies, Inc. or their respective owners. For specific trademark and licensing information, see www.idtdna.com/trademarks.


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