UCSF Navigation Bar

UCSF Departments of Pathology & Laboratory Medicine Home Page

Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

Internal Resources

BACTERIA CULTURE, BLOOD, ROUTINE

Item Value
Available Stat? No
Test code BLC
Performed by? Microbiology (Bacteriology)
Sendout? no
Price range $$
In House Availability 7 days
Principle The Microbiology Laboratory uses a continuous monitoring system, devised for detecting growth of microorganisms in specially prepared aerobic and anaerobic bottles. If microorganisms are present and are able to degrade the substrates, carbon dioxide is produced and will be detected as positive. Identification procedures including Gram stains, subculture and antimicrobial susceptibilities are then performed. The Laboratory will report by telephone any blood culture that becomes positive. Negative blood cultures are reported as no growth at 5 days. Notify the laboratory if you suspect fastidious or slow growing bacteria.
Interpretation Blood cultures are performed for:

1. Diseases with constant bacteremias (bacterial endocarditis). Take 3 separate blood cultures daily for 3 days.

2. Diseases with transient bacteremias when diagnosis is not established (typhoid, brucellosis, FUO). Take 1 blood culture about 2 hours before expected temperature rise. Repeat before each temperature rise, if known.

3. Diseases with transient bacteremias when diagnosis is reasonably established (pneumonia, "surgical" infection, meningitis, pyelonephritis, septic shock, etc.): Collect two blood cultures from different sites immediately before instituting treatment.
Container type Use standard aerobic and anaerobic blood culture bottles for routine bacteriology. Kits containing FAN (green cap) aerobic blood culture bottles are also available for patients on prior antimicrobial therapy or for fungal requests (See Mycology Culture, bloods). Blood culture kits are available from Lab Support Services (206-8199). See instructions below for blood collection.
Amount to Collect 5 - 10 mL
Collection Instructions Use standard aerobic and anaerobic blood culture bottles for routine bacteriology. Kits containing FAN (green cap) aerobic blood culture bottles are also available for patients on prior antimicrobial therapy or for fungal requests (See Mycology Culture, bloods). Blood culture kits are available from Lab Support Services (206-8199). See instructions below for blood collection.

The preparation of the venipuncture site is extremely important in the collection of a blood culture. The site should be prepared meticulously by scrubbing with Chloraprep applicator sponge, and care should be taken to avoid subsequent contamination of the area by finger palpation. Sterilize the exposed rubber diaphragms of the blood culture bottles with alcohol. Do not use any other sterilizing agent. Withdraw blood using Safety-Lok needle and direct draw adapter (available in blood culture bottle kits). Add 5 to 10 mL (10 mL recommended) of blood into each bottle, being careful not to inject any air bubbles into the anaerobic bottle (purple cap). DO NOT add more than 10 mL of blood to a blood culture bottle. Record patient's name and medical record number on a large removable label and place it over the bottle labels. Complete one requisition per 2 bottle set. Note time and date of culture on requisition. Leave inoculated Blood Culture Media at room temperature. Do not incubate or refrigerate until messenger pick-up.


Sample type Blood
Preferred volume 10 mL
Min. Volume 5 mL
Special instructions INDWELLING CENTRAL VENOUS AND ARTERIAL LINES: Indwelling central venous and arterial lines with stopcocks frequently become contaminated with multiple bacteria. Blood for culture should not be drawn through such lines unless they have been recently put in place. If blood is drawn through a line always indicate "line draw" on the requisition.
Synonyms Blood Culture;
Stability Leave blood culture bottles at room temperature until delivery to Lab.
References 1. bioMérieux BacT/ALERT 3D Technical Information. bioMérieux Inc.; Durham, NC. 2003.

2. Murray, PR. et al. Manual of Clinical Microbiology, 9th Ed., ASM Press, Washington DC, 2007.
CPT coding 87040
Last Updated 12/29/2008 2:54 PM
Search Our Test Menu
UCSF home page UCSF home page About UCSF Search UCSF UCSF Medical Center