This is a critical, time-sensitive test for diagnosing serious bloodstream infections (sepsis). It detects aerobic bacteria—germs that require oxygen—circulating in your blood. This 'Preliminary' report is our rapid alert. Our advanced, automated systems monitor your blood sample 24/7. The moment any bacterial growth is detected, we immediately alert your doctor. This allows them to start life-saving treatment days before the final identification is complete. This test requires a simple blood draw and is the essential first step in fighting a serious infection.