A method for identifying a second polynucleotide of interest based on selection of a first polynucleotide of interest, comprising: (a) obtaining a dataset associated with a plurality of polynucleotides, wherein the dataset comprises sequencing data for the plurality of polynucleotides, wherein each polynucleotide in the plurality of polynucleotides comprises a sample identification region, and wherein each sample identification region on each polynucleotide is unique to a single sample thereby associating each polynucleotide in the plurality of polynucleotides with a distinct single sample, wherein the sequence of the sample identification region of each polynucleotide from a first single sample is distinct from the sequence of the sample identification regions of the other polynucleotides in the plurality of polynucleotides from one or more samples distinct from the first single sample; wherein the first single sample comprises a B cell; and (b) selecting a first polynucleotide of interest associated with the first single sample from the dataset and identifying a second polynucleotide of interest in the first single sample based on the sample identification region of the first polynucleotide of interest, wherein the sample identification region of the first and second polynucleotides of interest are identical; and wherein (i) the first polynucleotide of interest comprises an antibody heavy chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody light chain nucleotide sequence; or (ii) the first polynucleotide of interest comprises an antibody light chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody heavy chain nucleotide sequence. (a) obtaining a dataset associated with a plurality of polynucleotides, wherein the dataset comprises sequencing data for the plurality of polynucleotides, wherein each polynucleotide in the plurality of polynucleotides comprises a sample identification region, and wherein each sample identification region on each polynucleotide is unique to a single sample thereby associating each polynucleotide in the plurality of polynucleotides with a distinct single sample, wherein the sequence of the sample identification region of each polynucleotide from a first single sample is distinct from the sequence of the sample identification regions of the other polynucleotides in the plurality of polynucleotides from one or more samples distinct from the first single sample; wherein the first single sample comprises a B cell; and (b) selecting a first polynucleotide of interest associated with the first single sample from the dataset and identifying a second polynucleotide of interest in the first single sample based on the sample identification region of the first polynucleotide of interest, wherein the sample identification region of the first and second polynucleotides of interest are identical; and wherein (i) the first polynucleotide of interest comprises an antibody heavy chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody light chain nucleotide sequence; or (ii) the first polynucleotide of interest comprises an antibody light chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody heavy chain nucleotide sequence. (i) the first polynucleotide of interest comprises an antibody heavy chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody light chain nucleotide sequence; or (ii) the first polynucleotide of interest comprises an antibody light chain nucleotide sequence, and the second polynucleotide of interest comprises an antibody heavy chain nucleotide sequence.