While visiting your injured squadmate at Huerta Memorial Hospital, enter the room across the corridor from your squadmate's in order to overhear a salarian scientist having a comm conversation about the missing prototypes.
WalkthroughNote: This mission must be completed before completing Priority: Tuchanka as it will be the last opportunity for the player to visit the Citadel before Priority: The Citadel II, after which it will no longer be available.
The biotic prototypes can be found by scanning Metaponto in the Aquila system of the Ismar Frontier cluster. After returning the biotic prototypes, you will receive 90 experience; no credits are given.
The salarian scientist would not have an icon marked on the map, and no manual trigger for conversation to complete the mission; instead, simply enter the lab where the scientist is and the remaining event will automatically play out.