Embryo cells are required for the test, thus the biopsy process completes in two steps:
• Opening of the Zona Pellucida (external shell of the embryo)
• Removal of the embryo cell(s)
The biopsy is performed on either Day 3 or Day 5.
• About 6 to 8 cells are present in a Day-3 embryo, so on Day-3, removal of only a single cell is done for the biopsy.
• A Day-5 embryo or a Blastocyst has multiple cells, and so numerous cells can be safely removed during the biopsy.
Different approaches for testing the embryo cells include PCR-technique, FISH-technique, aCGH-technique and NGS.