Chromosomal phase improves aneuploidy detection in non-invasive prenatal testing at low fetal DNA fractions.

Non-invasive prenatal testing (NIPT) to detect fetal aneuploidy by sequencing the cell-free DNA (cfDNA) in maternal plasma is being broadly adopted. To detect fetal aneuploidies from maternal plasma, where fetal DNA is mixed with far-larger amounts of maternal DNA, NIPT requires a minimum fraction of the circulating cfDNA to be of placental origin, a level which is usually attained beginning at 10 weeks gestational age. We present an approach that leverages the arrangement of alleles along homologous chromosomes-also known as chromosomal phase-to make NIPT analyses more conclusive.

The effect of processing and cryopreservation on nucleated umbilical cord blood cells.

Recovery of nucleated cord blood cells after storage in liquid nitrogen was evaluated. Red cells were depleted using Ficoll-Paque or Puregene red cell lyses. Freeze Medium contained 10% dimethylsulfoxide and 20% serum for cryoprotection.