Break out the kimono!
For decades, the art of silk dating was the stuff of old fashioned detective work. But now, scientists at the Smithsonian Museum’s Conservation Institute have created a sure-fire technique based on the natural deterioration of the fabric’s amino acids. And it only takes 20 minutes to perform!
From Smithsonian Science:
“Many things an animal makes are protein based, such as skin and hair. Proteins are made of amino acids,” explains Smithsonian research scientist Mehdi Moini, chief author of a recent paper in the journal Analytical Chemistry announcing the new dating method. “Living creatures build protein by using specific amino acids known commonly as left-handed [L] amino acids. Once an animal dies it can no longer replace the tissues containing left-handed amino acids and the clock starts. As L- changes to D-amino acids [right handed], the protein begins to degrade,” Moini explains. Measuring this ever-changing ratio between left-handed and right-handed (D) amino acids can be used as a scientific clock by which a silk’s age can be estimated. In controlled environments such as museum storage, the decomposition process of silk is relatively uniform, rendering D/L measurement more reliable.
The article “Dating Silk by Capillary Electrophoresis Mass Spectrometry,” appared in the scientific journal Analytical Chemistry, and was authored by Mehdi Moini; Mary Ballard, Smithsonian senior textile conservator; and Museum Conservation Institute intern Kathryn Klauenberg.