xGen® Lockdown® Probes are synthesized individually using the IDT Ultramer® synthesis platform, which incorporates the highest coupling rate (~99.6%) in the oligonucleotide manufacturing industry to provide high quality, long oligonucleotides.
The quality of each probe is then assessed by electrospray ionization mass spectrometry (ESI-MS; Figure 2 shows a typical trace). Even probes with high GC content can be synthesized. Probes that do no pass QC are documented, unlike probes from an array pool, where there is no way of knowing beforehand of their presence or absence.
Figure 2. ESI-MS of a Typical xGen® Lockdown® Probe. The trace of an xGen Lockdown Probe with 78.3% GC content is shown. Sequence: 5′ biotin–GCG GCG AGC GGA GAT CCG GGG CCT GCG CTG CGC ACT CGA GCC TGG CGG GCC GGC ACG GTG CGG GCC ATG AGC GGG GCG GTG CCC CAG GAC CTA GCG GTG AGT GGC GGC CGA GTC GGG CAC