Augmented Reality-Based Precise Oocyte Enucleation

Oocyte enucleation, removing nucleus and polar body in the oocyte, is a critical procedure for animal cloning. To preserve oocyte development potential, the removed cytoplasm in enucleation should be as little as possible. As the nucleus is invisible in the bright field, the operators usually have to blindly remove 1/4 to 1/3 of cytoplasm around the polar body in enucleation in order to completely remove the cell nuclei. The large amount of lost cytoplasm significantly decreases the development potential of the enucleated oocytes. The visualization of the nucleus is the key to reduce removed cytoplasm and achieve precise enucleation. In this paper, we conducted the statistics of the nucleus position relative to the first polar body for oocytes in MII stage through which the nucleus distribution area was obtained. Augmented reality was applied to superimpose the distribution area on the oocyte to visualize potential nucleus position. Using the statistical nucleus area, a micropipette penetrates the cell membrane, approaches the nucleus and extracts a set amount of cytoplasm to remove the nucleus and polar body automatically. Compared with the conventional blind enucleation method, our method increased enucleation success rate from 86.7% to 93.3% with less than 10% of cytoplasm removed. Through this, the cell survival rate after enucleation is improved from 57.1% to 91.4%.