This is different than submitting a sample for nutrient analysis where dry soil is preferred. Make sure that each bag is labeled with a permanent marker so that the diagnosis can be assigned to the correct area. If using a self-sealing bag seal it with tape also because the zippers often come open in transit. Handle samples carefully. Do not expose samples to direct sunlight or heat.
Nematodes are sensitive to high temperatures and UV light.
Leaving samples on the dashboard or in the back of a pickup truck can kill them quickly and negatively affect the accuracy of the diagnosis. Keeping the nematode sample in a cooler is best. The nematodes will be sandwiched between soil particles so rough handling will destroy them. For shipping and transport pack the samples well to minimized shifting. Next day delivery is best.