Base coupling in oligo synthesis is approximately 99% successful for each cycle; therefore, longer oligos have lower inherent purity. For a 50 nt DNA oligo, approximately 61% of the molecules will be full-length and correct; the other 39% of the molecules will be truncation and deletion products.
IDT recommends additional purification in general for oligos over 60 nt.
Ultramer® Oligonucleotides were developed specifically for researchers doing more demanding applications such as cloning, ddRNAi, and gene construction. Ultramer oligos undergo an enriched synthesis and desalting process available only with IDT proprietary synthesis systems and chemistries. This higher fidelity chemical synthesis will deliver longer oligos suitable for use in more demanding applications. Ultramer oligos must be 45–200 nt in length.
Visit Ultramer Oligos Catalog Page for more information.