> 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-reference_material-list/000008353.md).
# Scan feature differences between the iScan and NextSeq 550 Systems
The following Table lists the differences in scanning features between the iScan and the NextSeq 550.
**Notes:**
* Inter-platform variance between NextSeq550 and iScan devices is minimal.
* For MethylationEPIC Array:
Illumina data show that regardless of intensity, key performance specifications of MethylationEPIC are maintained.
To compare data generated on NextSeq 550 with that from an an iScan device, Illumina recommend using standard normalization algorithms that convert signal intensity to β-values. Normalization of the intensities results in the precise calculation of methylation changes on the NextSeq 550 as well as the iScan, and removes the effect of signal intensity differences prior to analysis.
**See the following for additional information.**\
[Infinium MethylationEPIC Array Scanning On the NextSeq 550 System](https://support.illumina.com/support-content/nextseq-control-sw-v4/nextseq-infinium-methylationepic.html)\
[NextSeq 500 and NextSeq 550 Sequencing Systems - Scanning Output Files](https://support-docs.illumina.com/IN/NextSeq_550-500/Content/IN/NextSeq/OutputFiles-Scanning_fNS_m550.htm)\
[iScan System - Generated Files](https://support-docs.illumina.com/ARR/iScan/Content/ARR/iScan/GeneratedFiles_fIS.htm)
\
\
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| *For any feedback or questions regarding this article (Illumina Knowledge Article #8353), contact Illumina Technical Support* [*techsupport@illumina.com*](mailto:techsupport@illumina.com?subject=Question%2FFeedback%20Regarding%20Illumina%20Knowledge%20Article%20#000008353%20-%20Microarray%20\&body=Dear%20Illumina%20Technical%20Support,%0D%0A%0D%0A)*.* |
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