Method of constructing a spatially barcoded surface

A method of making a spatially barcoded surface, comprising:

• (a) partitioning a surface of a solid support into rows by sealingly attaching to the surface a first channel template comprising a plurality of first channels, wherein the surface comprises a plurality of arrays of first oligonucleotides,
• wherein each array of the plurality of arrays comprises a plurality of discrete reaction sites, wherein each discrete reaction site comprises a first oligonucleotide of the first oligonucleotides attached to the surface by a 5′-end of the first oligonucleotide,
• wherein the plurality of arrays are arranged in orthogonal rows and columns, and
• wherein within each array of the plurality of arrays, each of the first oligonucleotides comprises a first barcode segment comprising a first barcode sequence associated with a location of the discrete reaction site within the array, and wherein each discrete reaction site of an array comprises a unique first barcode sequence within the array;
• and
• (b) reacting second oligonucleotides loaded into each first channel of the first channel template with the first oligonucleotides to form first spatial barcode oligonucleotides, wherein each first channel of the first channel template comprises a second oligonucleotide of the second oligonucleotides that comprises a second barcode segment, wherein each first channel of the first channel template comprises a unique second barcode sequence,
• wherein the rows of the plurality of arrays are at least partially coincident with the first channels of the first channel template.

A flow cell comprising a channel and a surface, wherein the surface of the channel comprises a plurality of arrays of spatial barcode oligonucleotides,

• wherein each array of the plurality of arrays comprises a plurality of discrete reaction sites, wherein each discrete reaction site comprises a spatial barcode oligonucleotide of the plurality of spatial barcode oligonucleotides attached to the surface by a 5′-end,
• wherein the plurality of arrays are arranged in orthogonal rows and columns,
• wherein within each array of the plurality of arrays, each of the spatial barcode oligonucleotides of the plurality of spatial barcode oligonucleotides within each array comprises a barcode segment comprising a first barcode sequence associated with a location of the discrete reaction site, wherein each discrete reaction site of an array comprises a unique first barcode sequence within the array, and
• wherein each array of the plurality of arrays in the channel comprises a spatial barcode oligonucleotide of the plurality of spatial barcode oligonucleotides that comprises a second barcode sequence associated with a location of an array within the channel.