Related Experiment Video
Updated: May 25, 2026

Hydrogel Nanoparticle Harvesting of Plasma or Urine for Detecting Low Abundance Proteins
Published on: August 7, 2014
B-type natriuretic peptide measured in serum--calibration using plasma samples for research purposes
M Severo1, M Pereira, P Bettencourt
1Department of Hygiene and Epidemiology, University of Porto Medical School, Porto, Portugal. milton@med.up.pt
Background:
We aimed to establish an equation for the estimation of the BNP concentration in plasma when only serum is available.
Methods:
We enrolled 27 subjects aged at least 45 years, participating in a Portuguese cohort study. Blood samples were collected in plastic whole blood tubes, containing either ethylenediaminetetraacetic acid to obtain plasma or clot activator to obtain serum. The natural logarithm of serum BNP was calibrated with the natural logarithm of plasma BNP using a linear equation.
Results:
The estimated regression parameters were 0.58 (95 % CI: 0.23 - 0.93) for beta0 and 1.01 (95 % CI: 0.90 - 1.11) for beta1. The absolute agreement between plasma BNP and that predicted by the equation according to the cut-off points 30 and 100 pg/mL were 96.3% (kappa = 0.92) and 96.3% (kappa = 0.91), respectively.
Conclusions:
Serum samples cannot be used to estimate absolute plasma concentrations, but serum BNP values and the calibration equation can be used to classify correctly the individuals with the usual cut-offs.
More Related Videos
Related Concept Videos
Blood Studies for Cardiovascular System II: CRP, Hcy, and Cardiac Natriuretic Peptide Markers
These markers indicate stress or strain on the heart muscle:
Natriuretic Peptides (BNP)
Cardiac myocytes produce these hormones in response to ventricular stretching...
Serum Studies: Renal Function Tests
Drug Dosing in Renal Diseases: Measurement of Glomerular Filtration Rate
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:

