This is special blood plasma from the secondary heart of an Eyemutant.

One singular property of the Eyemutant breed is the frequent occurance of double hearts in their bodies. The secondary heart performs all the same duties the primary heart does, but the level of stress on the heart is lower. This is possibly because the secondary heart is less affected by the emotions of the Eyemutant - that is reputed for being among the most emotional of the mutant species.