Abstract: Provided in some aspects are methods for light-controlled in situ surface patterning of a substrate comprising a step of blocking or ablating oligonucleotide molecules in a boundary region separating a plurality of spot regions, and attaching oligonucleotides to oligonucleotide molecules in a first one or more of the spot regions.

Abstract: The present disclosure relates in some aspects to methods and compositions for manufacturing molecular arrays using a hybrid approach comprising using non-contact printing (e.g., using inkjet printing, slot die coating, and/or blade coating) and photolithography-guided oligonucleotide hybridization and ligation. In particular, the molecular arrays can be used for determining spatial patterns of abundance and/or expression of a biological target in a sample.

Abstract: Provided in some aspects are methods for light-controlled in situ surface patterning of a substrate. Compositions such as nucleic acid arrays produced by the methods are also disclosed. In some embodiments, a method disclosed herein comprises using photoresist for photocontrollable hybridization and/or ligation of nucleic acid molecules, wherein photoresist removal allows hybridization and/or ligation of nucleic acid molecules at the exposed area. A large diversity of barcodes can be created in molecules on the substrate via sequential rounds of light exposure, hybridization, and ligation.

Abstract: A sample holder includes a first member featuring a first retaining mechanism configured to retain a first substrate that includes a sample, a second member featuring a second retaining mechanism configured to retain a second substrate that includes a reagent medium, and an alignment mechanism connected to at least one of the first and second members, and configured to align the first and second members such that the sample contacts at least a portion of the reagent medium when the first and second members are aligned.