> For the complete documentation index, see [llms.txt](https://knowledge.illumina.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://knowledge.illumina.com/microarray/general/microarray-general-faq-list/000008332.md).

# Which Fluorometric Quantification Method to Use for Quantifying Input DNA for the Infinium Assay?

Using the recommended amount of input DNA is vital to the success of the Infinium Assay. DNA used as input for the Infinium workflow must be double-stranded DNA (dsDNA).

**Recommended Methods**

Fluorometric quantification methods, such as **Qubit or PicoGreen**, are recommended to accurately measure the concentration of dsDNA extracted from fresh, frozen, or FFPE samples.

**Note:** If using Qubit, ensure that the assay kit selected is specifically for dsDNA quantification.

**Methods Not Recommended**

UV spectrophotometric methods, such as NanoDrop, are not recommended for DNA quantification because they do not accurately reflect the concentration of double-stranded DNA. However, UV spectrophotometry can be used to assess DNA purity and quality including 260/280 and 260/230 ratios. For additional guidance, refer to the DNA quality section of the Illumina Knowledge [Guidelines for Sample Preparation for Infinium Genotyping Assay DNA input](/microarray/general/microarray-general-reference_material-list/000002180.md).

Quantification values generated by the Agilent Bioanalyzer or TapeStation should not be used to determine DNA input amounts for Infinium assays.

**References:**

* [DNA Input Guidelines for Infinium MethylationEPIC Arrays](/microarray/general/microarray-general-reference_material-list/000002679.md)
* [Infinium Assay Modifications for FFPE Samples Used with Genotyping Arrays](/microarray/general/microarray-general-faq-list/000006007.md)

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| *For any feedback or questions regarding this article (Illumina Knowledge Article #8332), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000008332%20-%20Microarray%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |


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