Drop of dried human blood taken from a healthy individual. The drying shows regular patterns that vary only according to the composition of the blood. They are sources of information on the state of health of the individual. The researchers are trying to develop a novel method of diagnosing diseases affecting the composition of blood, based on the observation of dried blood samples. They will establish the characteristic imprint of a panel of diseases and build a database to reliably analyze these patterns. This technique would make it possible to avoid the multiple and costly analyzes that are currently being used.