A method and system for identifying mRNA present in a sample. A splice variant technique selects a set of possible exon-exon junctions based on exons of expected mRNA transcripts. The splice variant technique then selects indicator polynucleotides for the exon-exon junctions and detects the expression level of the indicator polynucleotides in the sample. The splice variant technique then may use a mathematical algorithm to identify possible splice variants in the sample from the observed expression levels.