The determination of the genotype of an in vitro-fertilized, human embryo prior to its implantation. The technique samples one blastomere from an eight-cell embryo, and the selected templates are amplified by the polymerase chain reaction (q.v.). Tests are then run to see if the templates contain mutant copies of the gene under study. Embryos free of the defect are used to start the pregnancy.
Subjects: Genetics and Genomics.