Ovarian resequencing enzymes were a type of enzyme used to facilitate the creation of hybrid offspring between two persons of different species.
Doctor Julian Bashir administered ovarian resequencing enzymes to Jadzia Dax in 2374 to allow her and her husband Worf to have a child together despite their normally incompatible physiologies. Bashir found that they appeared to have been working well, but Jadzia's untimely death at the hands of a Pah-wraith controlled Dukat precluded the possibility of a child being created. (DS9: "Tears of the Prophets")