The present disclosure provides methods and systems for processing nucleic acid molecules from one or more cells. A cell may be comprised in a cell bead. Processing may comprise uniquely identifying nucleic acid molecules. Nucleic acid molecules may be identified by barcoding. Barcoding may be combinatorial barcoding. Combinatorial barcoding may allow for generation of a large number of barcodes, thereby uniquely identifying nucleic acids from a large number of single cells. Combinatorial barcoding may be performed in successive operations. Successive operations may be performed in partitions.