Alternative journal entry:
A toxin tailored to turians was recovered from a Cerberus base. Find someone on the Citadel who can use it.
You can acquire this mission either by talking to the doctor at the Lab Services in Huerta Memorial Hospital or by finding the poison directly.
Walkthrough EditArrae: Ex-Cerberus Scientists in a corner of the main room on top of a box. It looks like a microscope.
After finding the poison give it to the doctor in the Examination Rooms section of the hospital. Upon completion, you will gain 5 Reputation, 30 experience and 1,000 credits. The Turian Sixth Fleet War Asset is also updated.
If you didn't find the poison during the mission it will be available for 1000 credits in the Spectre Requisitions store.