When submitting samples for testing, we reccomend the USPS, UPS or FedEx. If you samples are perishable, such as Fresh Flower or Edibles, we reccomend shipping them overnight with a ice pack or dry ice, available from most Walmarts in the Southern USA.
Please pack your samples in a secure container, such as vacuum sealed or ziplok bag, or a glass eyedropper bottle or a small box. Place your container in a plastic bag and then ship using the carrier's supplied packaging. The USPS (Post Office) has many sizes of Priority Mail boxes for free and the smaller one will get here in two business days for $7.90.
Sometimes samples are viscous (like honey) and can be difficult to homogenize before sampling. Take note of any separation of the sample before your package it and do what you can to mix it very good. Contact the lab if you need sampling supplies or any further info on packing samples for testing.