Patent ID: 7888017

Claim:
A method of determining a fetal aneuploidy by determining the number of copies of maternal and fetal target chromosomes, having target sequences in a mixture of maternal and fetal genetic material, comprising the steps of: a) obtaining maternal tissue containing both maternal and fetal genetic material; b) obtaining a mixture of maternal and fetal genetic material from said maternal tissue; c) distributing the genetic material obtained in step b) into a plurality of reaction samples, to randomly provide individual reaction samples that contain a target sequence from a target chromosome and individual reaction samples that do not contain a target sequence from a target chromosome; d) analyzing the target sequences of genetic material present or absent in said individual reaction samples to provide a first number of binary results representing presence or absence of a presumably euploid fetal chromosome in the reaction samples and a second number of binary results representing presence or absence of a presumably aneuploid fetal chromosome in the reaction samples, e) determining the presence or absence of a fetal aneuploidy by comparing said first number of step (d) with said second number of step (d), wherein a differential between the first number and the second number indicates the presence of a fetal aneuploidy.