Abstract: Embodiments of the present invention provide methods for the enrichment of rare microparticles, cells, or nucleic acids from a complex mixture using serial size exclusion filtration. Also provided are less invasive methods for detecting chromosomal or genetic abnormalities in a fetus, by enriching fetal microparticles in maternal plasma using serial size exclusion filtration, and isolating and analyzing the fetal nucleic acids from the fetal microparticles. Methods for diagnosis of diseases such as cancer are also provided, including enriching disease specific microparticles in the patient's plasma using serial size exclusion filtration, and isolating and analyzing the nucleic acids from the disease specific microparticles.

Abstract: Methods for enriching specific microparticles, such as fetal microparticles or disease specific microparticles, in a biological sample are disclosed. In certain embodiments, the methods include combining a biological sample with a molecule that binds specific microparticles, and separating fractions of the biological sample, wherein the fraction that contains the binding molecule is enriched for the specific microparticles. Also disclosed are methods for enriching fetal nucleic acids by enriching fetal microparticles in a fraction of the biological sample and isolating nucleic acids from the enriched fraction. Methods for facilitating prenatal diagnosis of fetal chromosomal abnormalities are disclosed. In certain embodiments, the methods include combining a biological sample with a molecule that binds fetal microparticles, separating fractions of the biological sample, isolating nucleic acids from the fraction enriched for fetal microparticles, and analyzing the nucleic acids for the presence of a mutation.