Focus images on the MiniSeq and NextSeq 500/550

At the beginning of Read 1 on the MiniSeq and NextSeq 500/550, the instrument will determine the best Z position (distance between the objectives and flow cell) where the clusters are well-focused. During this process, the instrument will take and save a series of Focus Images. Many of the images will be completely back, though some will show the clusters (clusters are visible in the images when the Z position is correct, allowing for proper focus of the clusters on the flow cell).
Technical Support can evaluate Focus Images to diagnose clustering issues (failed to cluster/ underclustering and overclustering) or an unstable focus model.
  • Location of Focus Images:
    • MiniSeq: D:\Illumina\MiniSeq Sequencing Temp[Run Folder]\Images\Focus
    • NextSeq 500/550: D:\Illumina\NextSeq Control Software Temp[Run_Folder]\Images\Focus
Example Focus Images:
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