cognate heavy and light chain pair of tcr t cell receptor and bcr b cell receptor in tandem in a synthetic and or in vitro amplified construct could place bumi tags at 5 u2032 and 3 u2032 ends as well as at internal fusion points where synthesized primers linkers are incorporated in another variation of the invention the target molecule species are all messenger rna species present in the sample and the landing pad sequence and the bumi tag is incorporated 5 u2032 of an oligo dt or anchored oligo dt first strand cdna primer or are incorporated 5 u2032 of a random hexamer primer for use in oligo dt or in random primed cdna synthesis respectively in another variation of the invention the target molecule species are specific sets of messenger rna species for example transcripts from complex loci that exhibit somatic cell rearrangement and or somatic hyper mutation these include immunoglobulin heavy kappa and lambda chain loci as well as t cell receptor alpha and beta chain loci in this instantiation the landing pad sequence and bumi tag are incorporated 5 u2032 of a gene specific region in the first strand cdna primer for gene specific cdna synthesis a gene specific forward or set of forward primers complementary to the region flanking the upstream end of the sequencing target is used for pcr based amplification or addition of adaptors for cloning based amplification unlike standard barcoding methods in addition to keeping the sample sources identifiable after mixing differently barcoded samples bumi tags allow for more accurate determination of the frequencies.