Iowa Code § 189.7: Preservation of sample.

After the sample is taken, it shall be carefully sealed and labeled with the name or brand of the article, the name of the party from whose stock it was taken, and the date and place of taking such sample. Upon request a duplicate sample, sealed and labeled in the same manner, shall be delivered to the person from whose stock the sample was taken. The label and duplicate shall be signed by the person taking the same. The method of taking samples of particular articles may be prescribed by the rules of the department.