Abstract: Aspects of the present invention are drawn to methods and compositions for the genetic analysis of regions of interest (ROI) from one or more starting polynucleotide sample(s). In certain aspects, adapter tagged polynucleotide fragments from a plurality of initial polynucleotide samples are pooled, circularized and amplified to produce an immortalized library. Multiple ROI's from this immortalized library are amplified (e.g., in independent iPCR reactions) to generate amplicons, and, in some embodiments, pooled to form a pooled ROI amplicon sample. In certain embodiments, the amplicons for each ROI amplicon in the pooled ROI amplicon sample are present at known molar or mass ratios. The pooled ROI amplicon sample can be analyzed/processed as desired, e.g., sequenced using next generation sequencing technology.