Exploring the stability of whole blood samples for remote health care applications towards reliable home-based blood testing.

ObjectivesTo evaluate the stability of commonly used biomarkers in whole blood under various storage conditions, in order to assess their suitability for home-based blood collection in remote care settings.MethodsWhole blood samples were stored at 4-8°C, 20-25°C and 37°C for up to 72 h. Six pooled samples and two healthy volunteer samples were aliquoted and analysed at four time points (T0, T24, T48 and T72 h). A panel of 47 routine chemistry and immunochemistry biomarkers was measured in all samples. Recoveries relative to T0 were compared to within subject coefficients of variation of the individual biomarkers.ResultsMost biomarkers remained stable at refrigerated and room temperature conditions up to 72 h with a subset of biomarkers, mostly proteins and tumour markers also showing good to acceptable stability at 37°C. Several biomarkers, including potassium, inorganic phosphate and iron, consistently fell outside acceptable limits under multiple conditions. Others, such as sodium, calcium, ferritin, aspartate aminotransferase and cytokeratin fragment 21-1, were unstable only at 37°C. A few transient deviations were observed, but these were not consistent over time.ConclusionsHome-based blood sampling is feasible for a broad range of biomarkers, provided that heat exposure during transport is minimised. These findings are a first step in the further validation of selected analytes under real-world, capillary blood sampling conditions.