# Library prep workflow frequently asked questions for the Illumina miRNA prep kit

**How does this kit capture miRNA?**

* RNAs with a 3′ hydroxyl group and a 5′ phosphate group (such as miRNA and piRNA) will be captured into the library. Generally speaking, any RNA molecule that is 50 bp or smaller, and has a 3′ hydroxyl and 5′ phosphate, will be robustly included in the library.

**What happens when the 3**’ **or 5**’ **adapters are NOT diluted for low RNA input amounts or serum/plasma?**

* Adapter dimers increase.

**Can customers store the primer/adapter dilutions that are made in the protocol? If so, for how long and at what temperature?**

* This is not recommended. It is best to make fresh dilutions for each batch/day.

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #9892), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000009892%20-%20Library%20Preparation%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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