Abstract: Provided in the present disclosure are a method and a device for determining a fraction of cell free nucleic acids in a biological sample and use thereof, wherein the method comprises: (1) sequencing nucleic acids of a biological sample having free nucleic acids, in order to obtain sequencing results for a plurality of sequencing data; (2) based on the sequencing results, determining the number of nucleic acid molecules with a length falling within a preset range in the sample; and (3) based on the number of nucleic acid molecules with a length falling within the preset range, determining the ratio of free nucleic acids in the biological sample.

Abstract: The current invention is directed to methods for noninvasive detection of fetal genetic abnormalities by large-scale sequencing of nucleotides from maternal biological sample. Further provided are methods to remove GC bias from the sequencing results according to the difference in GC content of a chromosome. The current invention not only makes the detection much more accurate but also represents a comprehensive method for fetal aneuploidy detection including sex chromosome disorders such as XO, XXX, XXY, and XYY, etc.

Abstract: The current invention is directed to methods for noninvasive detection of fetal genetic abnormalities by large-scale sequencing of nucleotides from maternal biological sample. Further provided are methods to remove GC bias from the sequencing results according to the difference in GC content of a chromosome. The current invention not only makes the detection much more accurate but also represents a comprehensive method for fetal aneuploidy detection including sex chromosome disorders such as XO, XXX, XXY, and XYY, etc.

Abstract: The present invention involves an analysis method of cellular chromosomes, particularly involves a method of analyzing whether a difference exists in the chromosome number between amniotic cells and standard cells by a sequencing method.