Abstract: In one example, a flow cell includes a base support and a protrusion over the base support, where the protrusion is a different material than the base support. The flow cell further includes a first functionalized layer over a first portion of the protrusion, a second functionalized layer over a second portion of the protrusion, and first and second primer sets respectively attached to the first and second functionalized layers.

Abstract: An example flow cell includes a multi-layer stack including a transparent base support; a patterned sacrificial layer over the transparent base support; and a transparent layer over the patterned sacrificial layer. The flow cell further includes first and second functionalized layers over different portions of the transparent layer, wherein at least one of the first and second functionalized layers aligns with a pattern of the patterned sacrificial layer; and first and second primer sets respectively attached to the first and second functionalized layer.

Abstract: An example of a flow cell includes a substrate, a plurality of chambers defined on or in the substrate, and a plurality of depressions defined in the substrate and within a perimeter of each of the plurality of chambers. The depressions are separated by interstitial regions. Primers are attached within each of the plurality of depressions, and a capture site is located within each of the plurality of chambers.

Abstract: An example of a flow cell includes a substrate, a plurality of chambers defined on or in the substrate, and a plurality of depressions defined in the substrate and within a perimeter of each of the plurality of chambers. The depressions are separated by interstitial regions. Primers are attached within each of the plurality of depressions, and a capture site is located within each of the plurality of chambers.

Abstract: A catalytically active substance includes a copper (I) sulfide mineral particle, and an alkyne functionalized molecule bound to a surface of the copper (I) sulfide mineral particle. In an example method, a copper (I) sulfide mineral is reacted with an alkyne functionalized molecule to form a catalytically active substance. The catalytically active substance is reacted with an azide functionalized molecule to couple the catalytically active substance with the azide functionalized molecule.

Abstract: An example of a flow cell includes a substrate; a first primer set attached to a first region on the substrate, the first primer set including an un-cleavable first primer and a cleavable second primer; and a second primer set attached to a second region on the substrate, the second primer set including a cleavable first primer and an un-cleavable second primer.

Abstract: One example of a flow cell includes a base support and a multi-layer stack positioned over the base support. The multi-layer stack includes a resin layer positioned over the base support; and a hydrophobic layer positioned over the resin layer. A depression is defined in the multi-layer stack through the hydrophobic material and through a portion of the resin.

Abstract: An example of a flow cell includes a substrate; a first primer set attached to a first region on the substrate, the first primer set including an un-cleavable first primer and a cleavable second primer; and a second primer set attached to a second region on the substrate, the second primer set including a cleavable first primer and an un-cleavable second primer.

Abstract: An example of a flow cell includes a substrate; a first primer set attached to a first region on the substrate, the first primer set including an un-cleavable first primer and a cleavable second primer; and a second primer set attached to a second region on the substrate, the second primer set including a cleavable first primer and an un-cleavable second primer.

Abstract: An example of a flow cell includes a substrate, which includes nano-depressions defined in a surface of the substrate, and interstitial regions separating the nano-depressions. A hydrophobic material layer has a surface that is at least substantially co-planar with the interstitial regions and is positioned to define a hydrophobic barrier around respective sub-sets of the nano-depressions.

Abstract: An example of a flow cell includes a substrate, a plurality of chambers defined on or in the substrate, and a plurality of depressions defined in the substrate and within a perimeter of each of the plurality of chambers. The depressions are separated by interstitial regions. Primers are attached within each of the plurality of depressions, and a capture site is located within each of the plurality of chambers.

Abstract: A catalytically active substance includes a copper (I) sulfide mineral particle, and an alkyne functionalized molecule bound to a surface of the copper (I) sulfide mineral particle. In an example method, a copper (I) sulfide mineral is reacted with an alkyne functionalized molecule to form a catalytically active substance. The catalytically active substance is reacted with an azide functionalized molecule to couple the catalytically active substance with the azide functionalized molecule.

Abstract: An example of a method includes providing a substrate with an exposed surface comprising a first chemical group, wherein the providing optionally comprises modifying the exposed surface of the substrate to incorporate the first chemical group; reacting the first chemical group with a first reactive group of a functionalized polymer molecule to form a functionalized polymer coating layer covalently bound to the exposed surface of the substrate; grafting a primer to the functionalized polymer coating layer by reacting the primer with a second reactive group of the functionalized polymer coating layer; and forming a water-soluble protective coating on the primer and the functionalized polymer coating layer. Examples of flow cells incorporating examples of the water-soluble protective coating are also disclosed herein.