D.C. Code § 48-107: Portion of sample analyzed to be sealed and retained.

In all cases where any drug or article of food shall be taken as a sample to be examined and analyzed, the person making the analysis shall reserve a portion of the sample, which shall be sealed, for a period of 30 days from the time of taking such sample, and in case of a complaint the reserved portion alleged to be adulterated shall, upon application, be delivered to the defendant or his attorney.