Candidate reference material could improve comparability of angiotensin II blood pressure testing between labs

A candidate reference material for angiotensin II could give laboratories a shared benchmark for validating methods and comparing blood pressure test results

A newly characterised candidate reference material could help laboratories obtain more consistent results when measuring angiotensin II (Ang II), a peptide hormone that regulates blood pressure and fluid-electrolyte balance and is used as a biomarker in tests related to vascular disease.

When laboratories measure the same biomarker using different methods, comparing their results reliably depends on traceable reference standards. For Ang II, that need is particularly acute as existing international reference materials for the hormone can be difficult to obtain and are subject to supply constraints.

To help close that gap, researchers from the South China National Centre of Metrology/Guangdong Provincial Institute of Metrology, Guangzhou, Guangdong, China, have developed and characterised a candidate reference material for Ang II. Reference materials function as a common measurement benchmark, allowing laboratories to validate analytical methods, assess performance and compare results across different measurement systems.

The material’s purity was determined using two independent techniques, isotope dilution mass spectrometry and the mass balance method. Although the two approaches rely on different measurement principles, they produced closely consistent results, supporting confidence in the assigned value. The material also showed strong bottle-to-bottle homogeneity, with an assigned value of 0.8734 g/g and a relative expanded uncertainty of 1.8 per cent (k=2).

Stability testing showed the material remained stable for at least 12 months at −20°C, and for at least seven days at both 4°C and 25°C under simulated transportation conditions. The researchers also compared their results against NRC ANG II-1, a commonly-used and certified reference material from the National Research Council Canada with the comparison meeting the accepted equivalence criterion, adding further support to the accuracy of the assigned value.

Beyond this specific material, the work could support method validation, laboratory quality control, performance evaluation and traceable measurement of Ang II more broadly, helping to make results from different laboratories and methods more directly comparable.

The researchers note that the study assessed the material’s metrological properties rather than its biological activity, which has not yet been examined. Further studies will be needed to establish whether it retains equivalent activity in vivo.

For further reading please visit: 10.1016/j.bioana.2026.08.001