A drop of blood on filter paper, allowed to dry and stored for future diagnostic purposes is considerably easier than the present-day, resource-consuming method using frozen blood samples in plastic tubes. In a new study, researchers at Uppsala University, Sweden have successfully measured 92 different proteins in millimetre-sized circles punched out of dried samples. They have shown that this method has great potential to save resources, to the benefit of early diagnostics and treatment.

Dried samples could be used for health services' routine checks. These could be performed in the fast-growing laboratory service sector, enabling people to have their state of health investigated without engaging medical and health services. The samples could also be used to set up very large-scale biobanks. Costs in the healthcare sector would plunge, more samples could be analysed and a high proportion of all blood samples taken could be saved.

One of the major limitations of dried samples, on the other hand, has been the small quantity of blood taken, which rules out many traditional analytical methods.

Proximity Extension Assay (PEA), based on research at Uppsala University, has been developed into a commercial product, Proseek Multiplex, by the Uppsala Company Olink. To date, the company has used the method to analyse a quarter of a million wet plasma samples.