# Saliva collection for Illumina DNA PCR Free library preparation questions

**Which saliva collection tubes have been tested for use with the Illumina PCR-Free kit?**\
GenoTek Oragene Discover series.

**Can saliva that has been collected in a different collection tube be used?**\
This protocol has been developed to work with the Oragene saliva collection tubes. Saliva samples collected into other tube types may not be stable under the same conditions and, therefore, the use of other collection tubes is not recommended.

**What is the purpose of the liquid in the lid of the Oragene Saliva collection tube?**\
This reagent lyses and stabilizes the saliva sample.

**How much of the DNA obtained from the saliva sample is human in origin?**

The amount of bacterial DNA present is variable between different samples and donors. In approximately 80% of the samples that were tested at least 80% of the DNA obtained aligned to the human reference sequence.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #3434), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000003434%20-%20Library%20Preparation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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