Methods of generating a nucleic acid signature for identifying particles associated in a partition are provided. In one aspect, the method comprises: partitioning a sample into a plurality of partitions comprising a particle comprising a solid support surface, the solid support surface having a plurality of oligonucleotide primers conjugated thereon, wherein the oligonucleotide primers comprise a barcode sequence, and wherein the partitions have 0, 1, or more than 1 particles per partition; providing in a partition a substrate comprising a barcode sequence or repeating clonal barcode sequences; and in the partition, associating a first particle conjugated to oligonucleotide primers comprising a first barcode sequence and a second particle conjugated to oligonucleotide primers comprising a second barcode sequence to a barcode sequence from the substrate, thereby generating a nucleic acid signature for the particles in the partition.