PreimpScreen PolB (13,16,18,21,22)
PreimpScreen PolB is designed for determining chromosome copy number in polar bodies. The first polar body is removed from the unfertilized oocyte, and the second polar body from the zygote, shortly after fertilization. The main advantage of the use of polar bodies in preimplantation genetic screening (PGS) is that they are not necessary for successful fertilization or normal embryonic development, thus ensuring no deleterious effect for the embryo. In some countries, where the legislation bans the selection of preimplantation embryos, polar body analysis is the only possible method to perform PGS. The biopsy and analysis of the first and second polar bodies can be completed before syngamy, which is the moment from which the zygote is considered an embryo and becomes protected by the law.
PreimpScreen Blas (13,18,21,X,Y)
PreimpScreen Blas is designed for determination of chromosome copy number in blastomeres. Cleavage-stage biopsy is generally performed the morning of day three post-fertilization, when normally developing embryos reach the eight-cell stage. The biopsy is usually performed on embryos with less than 50% of anucleated fragments and at an 8-cell or later stage of development. The main advantage of cleavage-stage biopsy over polar body (PB) analysis is that the genetic input of both parents can be studied, and therefore currently is the prevalent method when doing in situ hybridizations in preimplantation genetic screening.