How is aneuploidy testing done?
After the embryo is grown for three days in the laboratory, a technician can open the surrounding shell and remove a single cell (called a blastomere). This is called a biopsy. The cells left behind in the embryo generally continue to grow normally. The biopsied blastomere cell is attached to a glass microscope slide and analyzed by an outside reference laboratory using a technique called fluorescence in-situ hybridization, or “FISH”. This technique uses something called probes — small pieces of DNA that match the chromosomes to be analyzed — to count the chromosomes. These probes are attached to molecules contain colored markers. The probes are applied to the biopsied cell and subsequently attach to the chromosomes. Under a microscope, the chromosomes (identified by color) are counted and the geneticist can differentiate normal cells from aneuploid cells. Two days after the embryos were biopsied the geneticist issues a report detailing the chromosome test results for the embryos. The
