Method of Embryo Biopsy for Preimplantation Genetic Diagnosis

Abstract

Preimplantation genetic diagnosis (PGD) has been developed and offered the opportunity of
transferring only the detected normally genetic embryos to the couples at risk of inherited disease
transmission. Various methods of isolating the genetic material from preconception oocytes and
embryos in PGD have been developed. Polar bodies, blastomeres and trophectoderm cells were
isolated at various stages of preimplantation development for PGD. Several biopsy techniques have
been introduced, for instance, slitting, piercing and drilling with acid Tyrode’s solution or laser. The
zona pellucida drilling with acid Tyrode’s solution followed by aspiration method has been eventually
world-wide used for blastomere removal in PGD. Ca2+ and Mg2+ free medium has been used to
loosen the gap junction between blastomeres without any adverse effects in the biopsy procedure.
More researches in PGD including the techniques of genetic material isolation, however, should be
carried out to define its effectiveness and safety. The long-term development of children derived from
PGD should also be monitored to assure that PGD is useful and safe for universal practise.