# 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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