Brain abscesses were induced in mice following the intracerebral inoculation of live Staphylococcus aureus. Animals received intravenous injections of NIR-FLIVO 690 Tracer (kit #9112) or NIR-FLIVO 690 Free Dye Control (kit #9113) at 17 hours post-infection, whereupon signals were acquired 1 hour later from brain tissues ex vivo using an IVIS® Spectrum™ (Caliper Life Sciences). Strong caspase activity was associated with brain abscesses following administration of the NIR-FLIVO 690 Tracer (right image), whereas minimal signal was detected in animals injected with the NIR-FLIVO 690 Free Dye Control (left image).