The researchers found that when the slime mold Physarum polycephalum is exposed to light, it produces two unique substances called metabolites 1 and 2. These substances were identified through a technique called HPLC, which helps separate and analyze different compounds. The study aimed to understand the chemicals responsible for a phenomenon known as the "blue-light phenomenon". The discovery of these metabolites sheds light on the biochemical processes that occur in response to light exposure in this slime mold.