Haruko Obokata filed an appeal with the government-backed Riken institute Tuesday demanding a reinvestigation of allegations of misconduct against her.
The stem cell researcher has been accused of falsifying data in a published paper on STAP cells, a still unconfirmed advance in generating stem cells.
Obokata, 30, was hospitalized Monday due to "her poor physical and mental condition," her lawyer, Hideo Miki, said, adding she is still willing to speak at a news conference in Osaka slated for Wednesday.