Dried blood spots - simple and efficient sample collection for analyses of protein biomarkers

Recent results from Uppsala University and Karolinska Institutet demonstrate that self-collected blood in the form of dried blood spots works well in analyses of protein biomarkers for cardiovascular disease. Using these types of samples would mean simpler and efficient blood collection that could be done by the individuals themselves.

Blood is the most common form of sample used for a large battery of analyses in healthcare and diagnostics. The blood is usually collected using phlebotomy, e.g. with a needle in the arm, performed by trained personnel. Separated components from the blood such as serum or plasma used in the analyses need to be stored under controlled conditions to sustain longer storage without degrading. Researchers have now examined an alternative way of collecting blood samples that can be accomplished by the individuals themselves and that does not require cold storage – dried capillary blood from a finger deposited on a special paper card.

Several advantages

"Dried blood spots have several advantages: it is a less invasive method, meaning less inconvenience for the individual, which could be ideal for sample collection from children, at home and at workplaces, and would reduce costs," says Professor Karin Broman at Karolinska Institutet.

In the published study, 92 protein biomarkers related to cardiovascular diseases such as hypertension are studied in both dried blood spots and conventional blood samples collected from the same individuals at the same time. The dried blood spots were collected by the participants themselves at a construction site.

Self-collected samples

"We start from a 1.2-millimetre diameter punched piece of the dried blood drop. This is enough for characterising 92 proteins. Our analysis shows that we obtain the same results from punches taken within or between separate dried blood spots, meaning that a large number of comparable samples can be used from one or a couple of drops of blood. Previous research under laboratory conditions has shown that proteins can be analysed from dried blood spots, but this is the first time this is shown for a large number of proteins in self-collected samples under field conditions," says Stefan Enroth, researcher at the Department of Immunology, Genetics and Pathology, Uppsala University.

In the open-access paper published in BioEssays (Wiley), the authors also compare dried blood spots with separated serum.

"For the majority, but not all, of the studied proteins the results are highly similar. Additional research is needed to characterise which protein biomarkers work well using this method and which do not," says Enroth.

Elin Bäckström