This test is used to isolate and identify potentially pathogenic organisms causing bacteremia.  Bacteremia is the presence of viable bacteria in the blood stream. Bacteria can enter the bloodstream as a severe complication of infections (like pneumonia or meningitis), during surgery (especially when involving mucous membranes such as the gastrointestinal tract, or due to catheters and other foreign bodies entering the arteries or veins (including intravenous drug abuse). It is also ordered to assist in establishing the diagnosis of endocarditis.

Depending upon the clinical disease suspected, multiple blood culture collections may be required.