2023 · Practical Laboratory Medicine · open access
Capillary blood stability and analytical accuracy of 12 analytes stored in Microtainers
Fontaine & Saez
The finding, in our words
Fingerstick blood self-collected into BD Microtainer tubes and posted at ambient temperature for 24 h agreed acceptably with paired serum for 11 of 12 analytes, HbA1c, lipids, creatinine, urea, urate, liver enzymes and total protein, with only AST falling outside limits.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Although most kidney transplant recipients successfully collected capillary blood samples at home, haemolysis and transport conditions affected analyte stability. Agreement with venous sampling was acceptable for haemoglobin and creatinine, but potassium and haematocrit exceeded total allowable error limits.
A study of decentralised patient-centric microsampling found that 82% of untrained participants, 47 of 57, successfully self-collected acceptable fingerstick blood in Microtainer tubes. All 46 tested samples yielded accurate HIV viral suppression results compared to venipuncture, though this remote monitoring approach is limited to US courier services and temperature conditions.
TAP II capillary serum, both professionally collected and self-collected, correlated with venous serum at R > 0.9 for eight analytes including ALT, AST, cholesterol, HDL and triglycerides. Creatinine correlated acceptably but carried a consistent negative bias, and carbon dioxide, potassium and albumin did not reach acceptable agreement: the useful reading is that the panel has to be validated, not the device alone.
This UK consensus opinion outlines how clinical laboratories can validate self-collected capillary blood sampling against venous reference standards to achieve accreditation and facilitate the shift towards community-based patient care.
Capillary blood samples collected by staff or self-collected by participants showed strong correlation and clinically acceptable agreement with venipuncture for influenza haemagglutination inhibition titers. The small differences observed were not clinically meaningful, and adequate sample volume was achieved in most attempts, supporting the feasibility of decentralised serological testing.