Frequently asked questions

Our Scientific Applications Support team has assembled a list of frequently asked questions to help you find answers quickly. Filter using one or more categories to focus on specific topics, or use the search bar to perform a text search.

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Are you able to synthesize DNA oligos containing deoxyuridine (dU) instead of (deoxythymidine) dT?

We routinely make oligos that include deoxyuridine in place of deoxythymidine bases. The minimum synthesis scale for oligos containing dU is 100 nmoles. The modification code for internal deoxyuridine in a sequence is /ideoxyU/, while 5’ and 3’ incorporation have the modification codes of /5deoxyU/ and /3deoxyU/, respectively. More details, including pricing information, are provided on the Modifications page under the Products tab at

Custom DNA & RNA