Abstract: A method for concentrating and isolating nucleated cells, such as a maternal and fetal nucleated red blood cells (NRBC's), in a maternal whole blood sample. The invention also provides methods and apparatus for preparing to analyze and analyzing the sample for identification of fetal genetic material as part of prenatal genetic testing. The invention also pertains to methods and apparatus for discriminating fetal nucleated red blood cells from maternal nucleated red blood cells obtained from a blood sample taken from a pregnant woman.

Abstract: A method for concentrating and isolating nucleated cells, such as a maternal and fetal nucleated red blood cells (NRBC's), in a maternal whole blood sample. The invention also provides methods and apparatus for preparing to analyze and analyzing the sample for identification of fetal genetic material as part of prenatal genetic testing. The invention also pertains to methods and apparatus for discriminating fetal nucleated red blood cells from maternal nucleated red blood cells obtained from a blood sample taken from a pregnant woman.

Abstract: Methods for determining genetic status of a fetus from a sample of maternal blood comprise enriching nucleated red blood cells in the sample, including both fetal and maternal nucleated red blood cells. The nucleated red blood cells are then differentiated from all other blood cells in the enriched sample, and the nucleated red blood cells genetically screened to determine the genetic status. The nucleated red blood cells may be differentiated by immobilizing all enriched blood cells on a solid phase and locating the nucleated red blood cells for interrogation. Optionally, the nucleated red blood cells may be sorted and separated from other enriched blood cells in a liquid phase.