# Frequently asked questions for AmpliSeq for Illumina On Demand panels

AmpliSeq for Illumina On-Demand panels provide a choice of > 5000 pretested genes with known content relevant for inherited disease research, including hereditary cancer, primary immunodeficiency, hearing loss, and muscular dystrophy.

* Can the On-Demand panel be mixed with another custom panel?
  * No, each custom panel (On-Demand, Gene, Hotspot) is its own, distinct panel.
* How many PCR cycles should be used to amplify the custom targets?
  * Use the number of Primer Pairs as listed on the tube to inform the number of PCR cycles to use. The [reference guide](https://support.illumina.com/downloads/ampliseq-for-illumina-custom-and-community-panels-reference-guide-1000000036408.html) provides recommended PCR cycles based on primer pair/amplicon number.
* What are the minimum and maximum content (target) sizes?
  * Amplicons: 24-15,000 amplicons
  * Genes: 1-500 genes
* What is the amplicon length?
  * All On-Demand panels have a maximum amplicon size of 275 bp.
* Which genome builds are supported?
  * Human hg19 only.
* What gene format is needed when adding targets in DesignStudio?
  * HGNC format.
* How are the amplicons tested?
  * Genes have been tested via sequencing on the NextSeq 550 with a 2x151 run.
  * Not all gene combinations have been tested.
* What are the specifications for performance?
  * As this is a custom AmpliSeq design, Illumina does not provide specifications for performance.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #1048), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000001048%20-%20Library%20Preparation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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