Adding silk to blood samples keeps them fresh even without refrigeration, scientists reported Monday in the journal Proceedings of the National Academy of Sciences.
Many diagnostic tests look for disease-related proteins in a patient’s blood. But these proteins break down quickly if the sample isn’t chilled. In rural areas with no electricity, keeping blood samples stable is a challenge. Sometimes a spot of blood dried on cardboard can be used instead, but this method isn’t very effective.
To get around this problem, scientists mixed silk fibroin—a protein derived from silkworm cocoons—with blood and let it dry. They then retrieved the blood by dissolving its silky safeguard. Silk was more effective at preserving blood samples than dried blood spots, the researchers found. It may even evade the damage that can befall frozen blood samples during thawing.