In an open letter on its “expanded customer quality standards,” GNC said this week that as part of its new testing standards it agreed to with New York Attorney General Eric Schneiderman the retailer will perform DNA barcode testing on active herbal/botanical ingredients in its herbal supplements “prior to extraction.” Schneiderman used DNA barcoding to test finished herbal supplement products at a number of high profile retailers in New York and in February required the supplements to be pulled from...