Super mutant blood sample

The  is an item added to Fallout 3 in the Broken Steel add-on.

Surprisingly, it is a sample of Super Mutant blood used by the Brotherhood of Steel to keep track of how many Super Mutants a soldier has killed. The mutants will drop them if you have been given the related unmarked quest.

Appearances
s appear only in Broken Steel, a Fallout 3  add-on.