Spider silk has an ice nucleation activity

Several ice nucleating substances have been identified, which exist in vivo or can be extracted from biological materials. Spider silk, which has a strong ability for water condensation, has also been found to possess an ice nucleation activity. The freezing temperature of water droplets was higher in the presence than in the absence of spider silk. Moreover, by means of environmental scanning electron microscopy, it was observed that the activity is not due to foreign matter attached to the silk but to the silk fibroin itself.