Patent ID: 8859206

Claim:
A method for detecting quantity of a genetic sequence in a mixed population of human genomic nucleic acid sequences comprising at least a first and a second human genomic sequence, wherein the first sequence is a sequence of a wild-type allele of a locus and a second sequence is a sequence of a mutant allele of the locus, comprising: distributing or diluting a mixed population of cell-free, human genomic nucleic acid template molecules from a sample in which the fraction of mutant alleles is less than 20%, into a set comprising at least fifteen assay samples such that said at least fifteen assay samples each comprises less than ten template molecules; amplifying the template molecules in the assay samples, wherein an assay sample with a single template molecule forms homogeneous amplification products in the assay sample; analyzing by determining nucleic acid sequence of amplification products in the assay samples of the set with homogeneous amplification products to determine a first number of assay samples in the set which contain the first sequence and a second number of assay samples in the set which contain the second sequence; comparing the first number to the second number to ascertain a ratio which reflects the composition of the mixed population; identifying a mutation in the mixed population if a statistically significant fraction of assay samples comprises the second sequence.