Blood Culture - Aerobic and Anaerobic

Critical Value

Growth indicating a positive culture

Summary Test Name

Blood Culture - Aerobic and Anaerobic

Container Microbiology

Whole Blood in BD Bactec Bottles; Aerobic (Blue Top) & anaerobic (Purple Top); Bottles are available from Supply & Distribution and Value Link for inpatients and lab outreach at 717-531-4628 for outpatients.

Transport Time

Deliver to lab immediately after collection. Do not refrigerate.

Special Handling Instructions

Do not transfer blood collected from tubes containing anticoagulants such as citrate, heparin, EDTA, and oxalate into blood culture bottles. These chemicals may be toxic to some bacteria and could give false negative culture results.

Specimen Stability

12 hours at room temperature

Minimum Volume

1 ml/bottle

Specimen Transport

Room Temperature

Stat Availability

Not available

Test Turnaround Time Routines And Stats

Negatives finalized after 5 days; interim results daily

Patient Preparation

Always draw BD Bactec Bottles before other blood tests.

Disinfect skin with Chlorhexidine prep, swabbing concentrically from the center outward.

Allow Chlorhexidine prep to dry for 30 seconds before collecting blood specimens.

Disinfect bottle stoppers with alcohol swab.

Using a sterile needle and syringe collect 10-20 ml of blood. Add at least 3 ml of whole blood into each bottle.

Do not change needle during procedure.

If total blood collected is <5 ml, add entire volume to aerobic bottle.

Invert bottles to mix. Place patient label on the bottle. Do not cover the bar code label.

Preferred Volume

5-10 ml/bottle

Reference Value

No Growth

Test Results

Identification and sensitivity performed on potential pathogens

Additional Test Information

If Sub-acute Bacterial Endocarditis (SBE) is suspected, note on the request form. If Brucella is suspected, refer to Brucella Blood Culture in manual.

Three blood culture sets taken at least 15 minutes apart in the initial 24 hour period will detect >90% of positives.

In suspected SBE or low grade intra-vascular infection, draw three 10 ml specimens within the first 24 hours at intervals no closer than 1 hour. These should include include 2 collected at the earliest sign of a febrile episode

If bacteremia of unknown origin is suspected in patients on therapy and therapy cannot be suspended for a few days, draw 4-6 cultures within the first 48 hours. Obtain cultures immediately before the next dose of anti-microbial therapy.

In infants, 1-2 ml blood specimens are usually collected in a pediatric blood culture bottle.