# Diagnosing Suboptimal Clustering in Patterned Flow Cells Video

Although over clustering is not possible on a patterned flow cell, loading a library with a suboptimal concentration negatively impacts run data. In this video, we discuss preventing and diagnosing common clustering issues on patterned flow cells.

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{% embed url="<https://www.youtube.com/watch?v=jp9fNcR3O20&ab_channel=Illumina>" %}

Video length: 4:48 min

For further information, see [Cluster Optimization Overview Guide](https://support.illumina.com/downloads/cluster-optimization-overview-guide-1000000071511.html).

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