B-type Natriuretic Peptide (BNP)

Alternate Name: BNP

SAL Code:






Turn Around Time:

1 Day






Special Chemistry


Two-site immunoenzymatic (“sandwich”) assay

Specimen Requirements:

Primary Tube:


Primary Substance:

Plasma EDTA (FRZN)



Stable Ambient:


Stable Fridge:

24 hours

Stable Frozen:

Up to 9 Months

Rejection Criteria:

A non-EDTA sample received. Gross hemolysis; and/or specimens that were improperly labeled, collected, or handled.

Clinical Info:

The BNP assay is intended for the in vitro diagnostic use in the quantitative determination of B-type Natriuretic Peptide (BNP) in human plasma. This assay is indicated for the measurement of plasma BNP as an aid in the diagnosis and assessment of the severity of heart failure. In patients with acute coronary syndromes (ACS), this test, in conjunction with other known risk factors, can also be used to predict survival as well as to predict the likelihood of future heart failure.

Heart failure is an important clinical syndrome which compromises left ventricular systolic or diastolic function or a combination of both. Heart failure occurs when the heart is unable to pump blood at a rate sufficient for metabolic requirements. The most common causes are coronary artery disease, hypertension, valvular heart diseases and cardiomyopathies. Accurate and early diagnosis is important since effective therapeutic interventions (e.g., angiotensin converting enzyme inhibitors, beta-blockers) are available, which improve both morbidity and mortality. Studies indicate that BNP can be used for a wide range of clinical applications; including diagnosis, monitoring and prognosis. The circulating levels of BNP increase with decreasing left ventricular function and increasing clinical severity of heart failure, which makes it an appropriate test for diagnosis and staging of heart failure. Studies have also demonstrated that an increased level of circulating BNP correlates with higher incidence of cardiac events and mortality in patients with heart failure and Acute Coronary Syndromes, and supports utilization of BNP as a marker for patient prognosis.

Additional Information:

The lowest detectable level of BNP distinguishable from zero with 95% confidence is 2.0 pg/mL.
2.0 - 5000 pg/mL (extendable to 50000 pg/mL with dilution upon request).
Reference Range:
Please refer to the patient report for most up-to-date reference ranges.

Sample Collection:

Collect patient samples using standard phlebotomy techniques.

Click here for additional collection instructions.

After sample is drawn separate the plasma from the cells by centrifuging the sample for 15-20 minutes. Gently remove the plasma from the lavender tube using a disposable pipette paying attention not to disturb the buffy coat and aspirating plasma only. Transfer the plasma to a standard transport tube. Mark the tube as "Frozen EDTA plasma" and with the patient's information and freeze the tube as soon as possible.

If samples will be run at the laboratory within 24 hours of blood draw, a refrigerated non-centrifuged lavender top tube is acceptable.

Test Limitations:

Elevated levels of biotin may interfere with the accuracy of the BNP results. Specimens that contain biotin at a concentration of 38 ng/mL demonstrate a less than or equal to 10% change in results. Biotin concentrations greater than this may lead to falsely depressed results for patient samples.The recommended adult daily dietary intake for biotin is 30 µg/day. Patients that may take over the counter dietary supplements promoted for use in hair, skin and nail health may contain 5-100 mg of biotin, with some patients taking multiple pills per day. Pharmacokinetic studies in healthy adults have shown that, in subjects ingesting 5 mg, 10 mg, and 20 mg of biotin, serum concentrations of biotin can reach up to 73 ng/mL, 141 ng/mL, and 355 ng/mL, respectively. Subjects who take up to 300 mg of biotin per day may have plasma biotin levels as high as 1160 ng/mL.

Specimen Handling Instructions:

Frozen transport is preferred.

Test Information: