Spider silk has an ice nucleation activity

Several ice nucleating substances have been; identified, which exist in viv o or can be extracted from biological materials. Spider silk, which has a s trong 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 activi ty is not due to foreign matter attached to the silk but to the silk fibroi n itself.