Submission Instructions


Follow these instructions to prepare your samples for testing and diagnostic services. For instructions in a PDF format, click here.

For virus testing including hop latent viroid, leaf tissue is best. Be sure to take one leaf from each of the main growing stems. Leaves in the 3’’-5” range work well, with 3 leaves to make up one sample.

It is important to note that because of the latent nature of HpLVd, a minimum 3-4 tests on each plant is suggested before you can ensure a plant is truly negative. Testing should occur every 1-2 weeks. 

Pathogens followed by an asterisk (*) primarily infect the root system and underground plant parts. Samples for these pathogens should consist of roots near the crown of the plant, or a 3”-5” section of the crown that spans above and below the soil level.

Place the leaves or roots in a ziplock bag and clearly label it with your business name and strain type. Do this for each of the plants you would like to test. Each ziplock bag represents one test sample. If you are submitting multiple samples (e.g. 5 samples of ‘Blue Dream’ for viroid panel testing) and need to trace back individual samples, sequentially number the samples (e.g. 1, 2, 3, etc.). We will endeavor to track results and include sample numbers in the results report but are not responsible in the event that numbers are illegible or rub off in transit.

Pack your ziplock bags in a container with some cold packs. A cardboard box with an inner Styrofoam container works best. Please submit an electronic copy of your samples to and include a copy of your sample submission form with the plant samples. Fully tape the seams to limit odor.

Send samples to:

Dark Heart Lab Services
630 Pena Drive
Suite 600
Davis, CA 95618

Customers have reported positive feedback with UPS shipping services.

To learn more about lab services, contact

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