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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.

When do researchers use random (degenerate, wobble, mixed) base oligos?

Mixed bases are used in primers to bind to templates that contain variability or a mixture of sequences at the primer binding sites. Mixed bases can also be used to create diversity in clone libraries and in site directed mutagenesis. IDT offers random base oligos. Order them by using an upper case letter N or other IUPAC-IUB symbol (see table below). IDT offers two types of randomization, machine mix and hand mix. Machine mix bases are charged at the standard base price for the scale ordered. Hand mixing is done to provide custom ratios of the bases, and incurs an additional charge. When entering your sequence, the “Mixed Base” tab at the bottom of the page lists the IUB symbols and is where custom mix ratios need to be entered.

Now you can get gBlocks® Gene Fragments that contain up to 18 consecutive variable bases (N or K) for recombinant antibody generation or protein engineering.See for more information.

Custom DNA & RNA