Micromanipulation of cryopreserved embryos and cryopreservation of micromanipulated embryos in PGD

The possibility to employ cryopreservation in Preimplantation Genetic Diagn osis (PGD) should enlarge the opportunities for research and clinical activ ity. For these purposes, we tried three kinds of approaches on human abnorm al embryos: (1) cryopreservation of biopsied embryos; (2) biopsy of thawed embryos; and (3) biopsy of embryos derived from thawed oocytes. Our prelimi nary results show that: (1) biopsy of thawed embryos is feasible and FISH a nalysis is possible on both survived and lysed cells; (2) Optimization of f reezing/thawing procedures are necessary to obtain better survival rate aft er thawing of biopsied embryos; (3) Biopsy and FISH are feasible on embryos derived from thawed oocytes and they could be a good way to study the chro mosomal arrangement of these poorly investigated embryos. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.