A method comprising: (a) producing a first complementary polynucleotide from a first cell polynucleotide and a second complementary polynucleotide from a second cell polynucleotide from a plurality of immune cells from a sample with: (i) a first target primer comprising a region complementary to a same region of the first cell polynucleotides from the plurality of immune cells; (ii) a second target primer comprising a region complementary to a same region of the second cell polynucleotides from the plurality of immune cells; (iii) a reverse transcriptase comprising a non-template terminal transferase activity, wherein 3 or more identical non-template nucleotides are added to the 3' end of the first and second complementary polynucleotides; (iv) a plurality of molecular barcoded polynucleotides, each comprising: a molecular barcode, a 5' end region complementary to a region of a vessel barcoded polynucleotide, and a 3' end region complementary to the 3 or more non-template nucleotides; and (v) a vessel barcoded polynucleotide, thereby forming a first and a second single cell single-barcoded polynucleotide; (b) amplifying the vessel barcoded polynucleotide, thereby forming a first and a second single cell dual-barcoded polynucleotide; (c) amplifying the first and second single cell dual-barcoded polynucleotide, thereby forming a library of sequences comprising a variable region of the first cell polynucleotides or second cell polynucleotides, or a combination thereof; and (d) sequencing one or more of the sequences of the library, wherein (a) is performed in a vessel of a plurality of vessels, wherein the vessel comprises a single immune cell from the plurality of immune cells. (a) producing a first complementary polynucleotide from a first cell polynucleotide and a second complementary polynucleotide from a second cell polynucleotide from a plurality of immune cells from a sample with: (i) a first target primer comprising a region complementary to a same region of the first cell polynucleotides from the plurality of immune cells; (ii) a second target primer comprising a region complementary to a same region of the second cell polynucleotides from the plurality of immune cells; (iii) a reverse transcriptase comprising a non-template terminal transferase activity, wherein 3 or more identical non-template nucleotides are added to the 3' end of the first and second complementary polynucleotides; (iv) a plurality of molecular barcoded polynucleotides, each comprising: a molecular barcode, a 5' end region complementary to a region of a vessel barcoded polynucleotide, and a 3' end region complementary to the 3 or more non-template nucleotides; and (v) a vessel barcoded polynucleotide, thereby forming a first and a second single cell single-barcoded polynucleotide; (i) a first target primer comprising a region complementary to a same region of the first cell polynucleotides from the plurality of immune cells; (ii) a second target primer comprising a region complementary to a same region of the second cell polynucleotides from the plurality of immune cells; (iii) a reverse transcriptase comprising a non-template terminal transferase activity, wherein 3 or more identical non-template nucleotides are added to the 3' end of the first and second complementary polynucleotides; (iv) a plurality of molecular barcoded polynucleotides, each comprising: a molecular barcode, a 5' end region complementary to a region of a vessel barcoded polynucleotide, and a 3' end region complementary to the 3 or more non-template nucleotides; and a molecular barcode, a 5' end region complementary to a region of a vessel barcoded polynucleotide, and a 3' end region complementary to the 3 or more non-template nucleotides; and (v) a vessel barcoded polynucleotide, (b) amplifying the vessel barcoded polynucleotide, thereby forming a first and a second single cell dual-barcoded polynucleotide; (c) amplifying the first and second single cell dual-barcoded polynucleotide, thereby forming a library of sequences comprising a variable region of the first cell polynucleotides or second cell polynucleotides, or a combination thereof; and (d) sequencing one or more of the sequences of the library,