This disclosure provides, among other things, a method for analyzing a planar cellular sample. In some embodiments, the method comprises: (a) indirectly or directly attaching nucleic acid tags to binding sites in a planar cellular sample; (b) contacting the planar cellular sample with a solid support comprising an array of spatially addressed features that comprise oligonucleotides, wherein each oligonucleotide comprises a molecular barcode that identifies the feature in which the oligonucleotides is present; (c) hybridizing the nucleic acid tags, or a copy of the same, with the oligonucleotides to produce duplexes; and (d) extending the oligonucleotides in the duplexes to produce extension products that each comprises (i) a molecular barcode and (ii) a copy of a nucleic acid tag. Other embodiments, e.g., kits and the like, are also described.