# Flow cell overview for the NextSeq 1000/2000

NextSeq 1000/2000 flow cells are hollow glass slides with a single fluidics channel or lane etched with evenly patterned nanowells containing oligonucleotides complementary to the sequencing adapters on compatible prepared libraries. Lanes are imaged over smaller subcomponents, tiles. Tiles are small imaging areas on the flow cell. The camera takes two images per tile, one in the blue channel and one in the green channel and uses the differences in signal to determine base calls.

![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-41755b1a1a540a5fe3157e1bde6368f4bb7d5a52%2Fimage1.png?alt=media)

**Tile Naming Convention**

The tile name is a four-digit number that represents the tile position on the flow cell.

* The first digit represents the surface: 1 for the top surface or 2 for the bottom surface.
* The second digit represents the swath number: 1, 2, 3, 4, 5, or 6.
* The last two digits represent the tile number.
  * For P2 flow cells: swath numbers 1-4, the numbering starts with 01 at the outlet end of the flow cell through 11 at the inlet end. For swath numbers 5-6, the numbering starts with 01 at the inlet end and 11 at the outlet end.
* For example, tile name 1205 indicates top surface, swath 2, tile 05.

  ![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-77f6573344ea4f507c1b4b4ec05e6ffd0fdbbbb2%2Fimage2.jpg?alt=media)

**Figure 1**: Flow cell images.

![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-40b484a98472e1e383e8b3c242e7084b7c03b678%2Fimage3.jpg?alt=media)

**Figure 2**: P2 flow cell breakdown of lane, surfaces, swaths, tiles, and reference to reagent flow direction as viewed in Sequencing Analysis Viewer.

![](https://761066130-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGM9W2DuBTgEXv1ClCm8H%2Fuploads%2Fgit-blob-5850899b84f2bf337c018e00714112223b97500a%2Fimage4.jpg?alt=media)

**Figure 3**: P3 flow cell breakdown of lanes, surfaces, swaths, tiles, and reference to reagent flow direction as viewed in Sequencing Analysis Viewer.

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