Everything you need to know about shipping biological substances:

http://www.uab.edu/ohs/images/docs/bio/CourseMaterialCatA_06082016.pdf

https://www.ups.com/us/en/help-center/packaging-and-supplies/special-care-shipments/hazardous-materials/biological-substances.page?srchpos=1&srch_phr=Diagnostic%252BSpecimens

http://www.fedex.com/downloads/shared/packagingtips/pointers.pdf