Study on the detection of implantation site in rabbits.

In this study, an alkaline treatment was applied to the observation of implantation site in rabbits. Embryos in pregnant rabbits were stabbed to death on days 7, 8, 9, 10 and 18 of gestation. These animals were sacrificed on day 29. The uteri were removed, immersed in 2% sodium hydroxide and fixed with 10% buffered formalin. After the alkaline treatment, all of the implantation sites were clearly recognizable as white tissue since the other parts became fairly transparent. Even after the formalin fixation, all the implantation sites were similarly detectable. The mean area of implantation sites visibly increased after day 10. From all the results, the simple and accurate procedure including alkaline treatment was concluded to be useful for estimating implantation and pregnancy conditions in rabbits.