This chapter focuses on preparations for embryo biopsy. In order to avoid deoxyribonucleic acid (DNA) contamination, the embryo loading for biopsy and tubing of biopsied cells are carried out under two separate laminar flows preferably in two separate rooms. Embryos are cultured as per standard protocols to either day 3 or day 5. Preparation of Ca/Mg-free Hepes medium in droplets (25 μL) is done in culture dishes for 8 cell (day 3) embryo biopsy. For blastocyst (day 5/6) stage biopsy, preparation is in plain Hepes medium droplets (25 μL) supplemented with 20% Human Serum Albumin under cover of oil. While awaiting vitrification, numbered culture dishes are kept ready. In case day 3 embryo biopsy is carried out, embryo transfer is performed on day 5 by culturing the embryos further. Tubing of the biopsied cell has to be done under sterile conditions. The cells are washed 3 times in phosphate buffered saline (PBS) and gently inserted in sterile 0.2 mL polymerase chain reaction (PCR) tubes containing 2.5 μL of PBS. Although all these procedures require the skills of a trained embryologist, some difficulties may be encountered, which are mentioned in this chapter.