In 1912, Hahn and Meitner moved to the newly founded Kaiser Wilhelm Institute (KWI) for Chemistry. Hahn accepted an offer from Fischer to become a junior assistant in charge of its radiochemistry section, the first laboratory of its kind in Germany. The job came with the title of "professor" and a salary of 5,000 marks per annum. Meitner worked without salary as a "guest" in Hahns section. Later that year, perhaps fearing that Meitner was in financial difficulties and might return to Vienna, since her father had died in 1910, Planck appointed her his assistant at the Institute for Theoretical Physics in the Friedrich Wilhelm University. As such, she marked his students papers. It was her first paid position. Assistant was the lowest rung on the academic ladder, and Meitner was the first female scientific assistant in Prussia.
Proud officials presented Meitner to Kaiser Wilhelm II at the official opening of the KWI for Chemistry on 23 October 1912. The following year she became a Mitglied (associate), the same rank as Hahn (although her salary was still less), and the radioactivity section became the Hahn-Meitner Laboratory. Meitner celebrated with a dinner party at the Hotel Adlon. Hahn and Meitners salaries would soon be dwarfed by royalties from mesothorium ("middle thorium", radium-228 also called "German radium") produced for medical purposes, for which Hahn received 66,000 marks in 1914, of which he gave ten per cent to Meitner. In 1914, Meitner received an attractive offer of an academic position in Prague. Planck made it clear to Fischer that he didnt want Meitner to leave, and Fischer arranged for her salary to be doubled to 3,000 marks.
The move to new accommodation was fortuitous, as the wood shop had become thoroughly contaminated by radioactive liquids that had been spilt, and radioactive gases that had vented and then decayed and settled as radioactive dust, making sensitive measurements impossible. To ensure that their clean new laboratories stayed that way, Hahn and Meitner instituted strict procedures. Chemical and physical measurements were conducted in different rooms, people handling radioactive substances had to follow protocols that included not shaking hands, and rolls of toilet paper were hung next to every telephone and door handle. Strongly radioactive substances were stored in the old wood shop, and later in a purpose-built radium house on the institute grounds.