“…At this, the removal of cumulus cells using Vortex in hyaluronidase solution and enzymatic removal of zona pellucida in these periods did not result in the separation of PB1 from the surface of mature oocytes [52]. Since with the absence of zona pellucida, the first polar body PB1 stays on the oocyte surface only under the linkage with the metaphase plate, PB1 is the pointer of the precise location of maternal chromosomes [53].…”