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Large image view: Tracing marijuana to its roots

²ÝÁñÉçÇø photo by Marmian Grimes

Matthew Wooller, director of the ²ÝÁñÉçÇø Stable Isotope Facility, holds a jar of calibration standards in the facility's weighing room. The facility uses benzoic acid as a calibration standard for its instruments.

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