Mei Xiang. (Sarah L. Voisin/THE WASHINGTON POST)

Mei Xiang, the female giant panda, was artificially inseminated Sunday and Monday in what could be the zoo’s final attempt to impregnate her.

Despite the dwindling hope — it is believed that Mei has a less than 10 percent chance to get pregnant — the zoo’s live tweets (@NationalZoo) throughout the procedure maintained an air of optimism.