ISTA is the International Seed Testing Association. The OSU Seed Lab is an ISTA Accredited Member Lab. Learn more about ISTA by visiting their website.


Many seed-importing countries require an international certificate issued by an ISTA accredited laboratory. An ISTA certificate from the originating country can be used to verify acceptability by the importer before the seed is shipped, and may speed the process through customs and quarantine, preventing potential delays and economic problems for the shipper and/or the importer. The certificate comes in two colors, depending on customer needs: orange and blue.


ISTA Orange International Seed Lot Certificate. The certificate represents the seed lot as a whole, therefore, seed lot preparation, lot size, lot identification, and seed sampling must follow ISTA guidelines. The lab is responsible for both sampling and testing. Our authorized samplers are located in the Pacific Northwest and California. Please contact the lab to see if a sampler is available in your area, or if you are interested in becoming an ISTA sampler.

ISTA Blue International Seed Sample Certificate. Customers provide the seed sample which the lab then tests. The lab does not take responsibility for the sampling process and the certificate represents the submitted sample. This service can be provided for samples obtained by anyone. There is no lot size requirement.

Which One? It depends on what is required by the importing country/importer. Consult import requirements of the receiving country and the buyer prior to sampling.


We are accredited for purity (P), other seed determination (OSD), germination (G), tetrazolium (TZ), moisture (M), 1000 seed weight determination (1000wt), and endophyte (Lolium spp. and Festuca spp.). The lab is also accredited to perform testing on coated seed (except TZ). As long as the customer requests an approved ISTA test such as purity or germination, results for non-ISTA tests such as grow-out or ploidy can also be reported on the ISTA certificate under Other Determinations.


We are accredited for all species listed in the ISTA Rules. Some species such as Meadowfoam (Limnanthes alba), Seashore paspalum (Paspalum vaginatum), Chia (Salvia hispanica), and many native species are not in this list yet. We are not accredited for mixtures.


Orange Certificate: The customer prepares the seed lot for sampling according to ISTA guidelines, fills out the ISTA certificate request using Online Services, and sends it to the lab. We review the application for complete information, check lot size requirements against the ISTA rules and arrange for a sampler. Samplers are not available in all areas. Speed of sampling depends on sampler availability. The sampler delivers the seed sample to the lab. Upon completion of tests, the lab mails the certificate to the customer.
Blue Certificate: The customer samples the seed, fills out a request for the ISTA certificate and delivers the seed and completed application to the lab, either by mail or in person. Blue Certificates can also be ordered for samples already at the lab. Upon completion of tests, the lab mails the certificate to the customer.


Sampling (Orange only): Our ISTA sampling is performed by official seed samplers from several state agencies in the Northwest who have been trained on ISTA sampling and authorized by the lab. The sampling fees vary somewhat depending on what agency performs the sampling, and are billed by the sampling organization.
Testing: Fees are generally similar to our AOSA test prices. Some prices for ISTA tests may differ somewhat from standard AOSA test fees due to differences in amounts of seed required for testing. Please see the Testing Fees page.
Certificate (Orange or Blue): Included in the cost of testing. Duplicate, Provisional, and revised certificates incur an additional charge that can be found on the Testing Fees page.