xGen® Blocking Oligos are high quality, individually assessed oligonucleotides that have been developed for use in in-solution hybrid capture before next generation sequencing. Blocking Oligos bind to a designated strand of platform adapter sequences (usually the inverse of the synthetic adapter) to help prevent non-specific binding, improve the number of reads on-target, and increase the depth of enrichment. IDT offers 2 types of blocking oligos—xGen Universal Blocking Oligos and xGen Standard Blocking Oligos—each with its own method of ordering.
Start at www.idtdna.com/xgen by selecting xGen Blocking Oligos or Learn more about xGen Blocking Oligos to go to the Blocking Oligos page.
If you have specific requirements not met by these blocking oligos, you can configure your own xGen Custom Blocking Oligos (see below).
xGen Universal Blocking Oligos
xGen Universal Blocking Oligos block multiple indexed adapters simultaneously using a single oligonucleotide. They reduce the complexity of the workflow and increase capture throughput without a loss in performance. To order Universal Blocking Oligos:
- Under xGen Universal Blocking Oligos, click the Order button corresponding to the appropriate platform (Figure 1). You will be taken to the ordering page.
- In the Quantity box, enter the number of 10- and/or 25-reaction Blocking Oligos you need (Figure 2, step 1).
- xGen Universal Blocking Oligo – TS-p7(6 nt) corresponds to Illumina adapters 1–12 or any 6 nt index adapter.
- xGen Universal Blocking Oligo – TS-p7(8 nt) corresponds to Illumina adapters 13–27 or any 8 nt index adapter.
- Click Add to Order to complete the ordering process through your cart (Figure 2, step 2).
Figure 1. Click the Order Button for xGen® Universal Blocking Oligos for the Appropriate Sequencing Platform.
Figure 2. Select Quantity of xGen® Blocking Oligos Required (1) and Add to Order (2).
xGen Standard Blocking Oligos
xGen Standard Blocking Oligos are designed for low throughput target capture. They are available predesigned for Illumina TruSeq®, Ion Torrent®, and Roche 454 libraries. To order Standard Blocking Oligos:
- Under xGen® Standard Blocking Oligos, click the Order button corresponding to the appropriate platform (Figure 3). You will be taken to the specific order page for that platform. If the platform you are using is not listed, you can order xGen Custom Blocking Oligos (see below).
- On the next page, select the blocking oligos corresponding to the adapters you want to block (Figure 4, step 1). You can select all by clicking on the check mark button.
- Click on the plus button to configure the selected Blocking Oligos (Figure 4, step 2).
- Under II. Configure, click on the check mark to configure all Blocking Oligos or select individual Blocking Oligos for specific configuration (Figure 4, step 3); and adjust Yield (10 nmol or 25 nmol) and Purification (HPLC or Standard Desalt) for each Blocking Oligo. The default is set to 25 nmol and HPLC Purification. Do nothing if you want to proceed with these specifications.
- At the bottom right of the page, click on the >>> III. Review N items button (Figure 4, step 4).
- Review your selections on the next page and click I’ve completed my configuration (Figure 5). You can still make changes to your Blocking Oligo choices, yield, and purification by scrolling to the very bottom of the page and clicking in the left-hand corner on II. Configure Items <<< . Note: Items added to the cart cannot be edited; they can only be removed.
- Click Add N xGen Blocking Oligos to Cart (Figure 6) to complete the ordering process through your cart.
Figure 3. Click on the Order Button for xGen® Standard Blocking Oligos for the Appropriate Sequencing Platform.
Figure 4. Select and Configure Your xGen® Standard Blocking Oligos. Select the required Blocking Oligos (1) and add (2) them to the configuration panel. You can select individual or all Blocking Oligos in the configuration panel (3) to adjust manufacturing specifications. Click Review Button (4) to review selections.
Figure 5. Review Specifications for xGen® Standard Blocking Oligos and Complete Your Configuration.
Figure 6. Add xGen® Blocking Oligos to Your Cart and Complete the Ordering Process.
xGen Custom Blocking Oligos
You can design custom blocking oligos for adapters not listed on the IDT website. To order xGen Custom Blocking Oligos, use the Order button for the appropriate scale of Custom xGen Blocking Oligos you require. Input your sequence and associated information and select any modifications, on the oligonucleotide entry page, and then click ADD TO ORDER to complete the ordering process through your cart.
See xGen Blocking Oligos for further information, or contact our NGS specialists at firstname.lastname@example.org.