We have prepared this information to answer basic questions about the OSU Seed Lab and seed testing. See the ISTA FAQ for additional information about getting ISTA Certificates.


General Information

What are the major services of the lab?

The major service at the lab is seed testing, which is used to determine the quality of seed. Seed Testing is used for compliance with federal seed labeling laws, seed certification, Sod quality labeling, ISTA certificates, and other uses. In addition, the lab conducts applied research to improve testing methods and to assist industry customers. Hands-on workshops are also offered as educational events for seed industry customers.

What kind of samples does the lab test?

We test a broad range of samples, including official, certified, commercial, research, regulatory, and any sample pulled by seed growers, companies, etc.

Can the lab test samples from other states or countries?

Yes. The majority of samples come from within Oregon, but we can test samples from other states and countries. We have received samples from as far away as Alaska, North Carolina, Florida, Uruguay, and Australia.

What tests does the lab offer?

We offer a full complement of standard seed tests, including purity (together with a range of exams), germination, tetrazolium, vigor, ploidy, endophyte, species/cultivar identification, and many specialized tests. For more information on specific tests, please see the seed testing services page.

What testing rules does the lab use?

The testing rules used depends on the type of tests requested, and the destination of the seed. Rules we use include: AOSA (Association of Official Seed Analysts), ISTA (International Seed Testing Association), and Canadian Methods and Procedures for Testing Seed. Tests and evaluations can also be done for specific requirements, such as for Australia, New Zealand, Mexico, etc.

What species can the lab test?

The great majority of samples received are grass seeds, but we also test seeds of trees, cereals, legumes, oil crops, flowers, vegetables, native species, shrubs and others. Given this diversity, we participate in several proficiency test programs and maintain a very large reference seed collection (herbarium).

Can I visit the seed lab?

The lab encourages scheduled visitors (seed growers, cleaners, shippers, students, and the general public) to come and see our operation. Please contact us to set the date and time and to arrange a tour guide.

What are the charges for our services?

The fees for testing services are available on the testing fees page. Fees for research depend on the type of research needed. Fees for educational events are specific to the event and will be announced when they are coordinated.

Do you offer volume discounts?

Yes. We offer volume discounts under special circumstances for some germination and pathology testing. Please contact us for more information.

Sampling the Lot

Is the sample for Oregon Certification?

Samples for Oregon Certification can be obtained by authorized samplers of Oregon Seed Services (ph: 541-737-4513).  The sample is submitted in person by the sampler or through a secure mail service. Login to the ecertification site to fill out a sample certificate.

Is the sample for an ISTA Orange International Certificate?

Samples for the Orange International Certificate (OIC) can be obtained only by samplers authorized by the OSU Seed Laboratory. The sample is delivered to the lab in person or by a secure courier.

Is the sample for ISTA Blue International Certificate?

Samples for the Blue International Certificate (BIC) can be obtained by anyone. All certification samples submitted to the lab by Seed Certification personnel or by private individuals qualify for the BIC, provided sufficient seed is submitted.

Where do I find sampling manuals? 

For detailed sampling procedures you may want to check the AOSA Rules for Testing Seed, ISTA International Rules for Testing Seeds, ISTA Handbook on Seed Sampling, American Association of Seed Control Officials (AASCO) Handbook on Seed Sampling, or the Oregon Seed Certification Service Guide for Certification Samplers and Taggers. You may also contact us directly.

Submitting Samples

How do I prepare a sample?

Samples are submitted in secure bags or envelopes. Each sample should be properly identified with the crop kind, tests requested, identification (lot or reference number), and any treatment used. To avoid spillage in transport, place the sample bag inside a Ziploc or plastic bag.  Samples for moisture testing must be submitted in a sealed Ziploc bag to avoid moisture exchange. Live plant materials for grow-out need to be submitted with wet paper towels to protect the root system, and transported using the fastest service. Using our order forms will ensure we get all the information we need.

How much seed should be submitted?

A minimum of 2500 seeds is required by both AOSA and ISTA for a purity test. Any bulk exam such as noxious or ISTA complete OSD requires 25,000 seeds. Germination requires 400 seeds; TZ requires 200 for AOSA and 400 for ISTA. These are minimums; in practice at least 10% more seed is needed, and viability testing may require two or three times the minimum in some situations. For a complete set of common tests (purity, noxious, germ), the following are guidelines for common seeds. Please call us if you have any questions or need more specific information.

Suggested Sample Weights
Crop type Sample Weight
Small-seeded grasses (bentgrass, bluegrass), fine fescue, orchardgrass, small clovers (e.g. alsike, white) 60g
Large-seeded grasses (tall fescue, ryegrass), crimson clover, rape, canola, millet, flax, or seeds of similar size 150g
Alfalfa and red clover 150g (1000g for Certified seed)
Proso millet, sudangrass, hemp, or seeds of similar size 500g
Cereal grains, vetches, sorghums 1000g
Large-seeded vegetables (beans, corn, squash, beets, etc.) 550g

Small-seeded vegetables (broccoli, tomato, pepper, onion, etc.).  Varies by species.  

Typically 60g for purity & noxious exam

800 seeds min. for germination

Medium-seeded vegetables (spinach, etc.).  Varies by species.

Typically 260g for purity & noxious exam

800 seeds min. for germination

What is the best way to send it safely?

Make sure each sample is securely enclosed in a leak-proof bag, such as a Ziploc. If using paper bags, make sure the corners do not leak seeds. Plastic bags seem to be more resistant to heavy handling. Pack the bags into a sturdy box and use packing material to keep them from shifting around. Put order forms or other identification and testing information in the box. Tape the box securely and send it to us.

Can I drop it off at the lab?

We can accept Commercial samples from our customers but Certified samples must be delivered by our samplers or an authorized representative from OSCS or ODA. Our hours are 8am to 5pm (closed for lunch 12pm-1pm), Monday through Friday. If you need to come during lunch (12pm-1pm), please call ahead to ensure that someone will be here to meet you. We also have an after-hours sample drop by the lab front door. It does not accept boxes, so please make sure that individual samples are each completely labeled.

Does the lab retain samples on file after testing?

The lab retains samples for a minimum of two years. Customers may request that excess seed be returned after testing (charges may apply), but the lab must retain some seed to comply with federal regulations. In most cases, the file samples can be used for additional tests at customer request.

Speed of Testing

What is the regular speed of testing at the lab?

The regular speed depends on the number of samples currently in process at the lab. Samples are tested in the order in which they arrive. Turnaround times range from a few days in the slower season (winter and spring) to a week at the peak of the busy season (summer and fall). The Testing Flow Report, which is updated daily, has current information on how many samples are in the purity testing process, and the date of arrival of the samples the Purity and Germination Departments are currently working on. 

Can I rush my sample?

We offer a rush service. Purity results will be available within 1-2 working days after the rush request is received. When a rushed sample also has tests ordered such as tetrazolium and germination, these are included in the rush service without additional charge to the customers. Please note that some tests are not able to be rushed, and that during the peak of our busy season (July-Sept) the availability of rush service on a particular day may be reduced if a high volume of rush requests are received. The fee for rush service can be found on the testing fees page.

Does my sample have to be pre-chilled?

Pre-chilling (or cold stratification) is a method of breaking or reducing dormancy and is required by the testing rules for fresh and dormant seed of many species (see the table below). Any deviation from the prescribed rule is noted on the testing report. If you wish a sample to not be chilled, indicate "no chill" VERY CLEARLY on the sample. Be aware that your germination results may be poor if your seed has a high level of dormancy and is not pre-chilled.

Pre-Chill Guidelines for Common Crops
Crop Pre-chill?
Ryegrass Current crop year (until approx. December)
Tall fescue, orchardgrass Current crop year
Bluegrass, bentgrass, fine fescues Current and previous crop years
Clover No
Grains No

How long until I get my germination test results?

The duration of a germination test is determined by the testing rules. It varies for each species and may be different for AOSA or ISTA rules. We do a count every 7-days on nearly all species (e.g. species requiring a 10-day final count do not get a 7-day preliminary count). Tests are finished early if the sample has reached its full germination potential (i.e. no fresh seeds remain). Germination is a natural process and determining if a sample has reached its full germination potential before or by the end of the prescribed time is at the discretion of the analyst. The table below lists AOSA germination durations for commonly tested crops. Please contact us for ISTA duration rules. 

AOSA Germination Durations for Commonly Tested Crops
Ryegrass 14 days
Tall fescue 14 days
Fine fescues 21 days
Kentucky bluegrass 21 days
Colonial and creeping bentgrass 28 days
Orchardgrass 21 days
Grains (wheat, barley, oat) 7-10 days
White and red clover 7 days


How long does TZ take?

Tetrazolium (TZ) results are usually available within 1-2 business days. Exceptions to this fast process are highly contaminated samples and some native species. If the TZ test is completed before the purity test, it will be reported with the purity report.

What can I do to ensure the quickest test results?

Several things can contribute to faster processing of any sample without ordering a rush: clear and accurate sample identification, ordering all tests at once, entering samples on the web, ordering Crop and Weed exam with the original purity so that it can be converted to UGS or Sod Quality report (for many species) on short notice.

Access to Test Results and Reports

Can I get early results?

Yes. We encourage our customers to download reports, access their results, and enter sample information online. Our goal is to reduce mailing. Our database has a secure customer login. This allows you access to test information and results as soon as they are available.

Can I get official test results online?

Yes. Reports are available online to customers through a secure login. The reports are in the common PDF format.

Who can see my test results?

Only people or companies listed on the sample certificate or added as CCs can see your test results. We do not e-mail test reports as email is not secure enough for this purpose.

How do I get a report corrected?

Contact the lab immediately. We will investigate and issue corrected reports as soon as possible. If the correction is due to incorrect information being supplied to the lab, we may charge a fee. Note that some corrections for Certified seed, such as a change in lot number, may require sampler verification which increases turn around time. All changes to certified samples that are not due to lab error must be requested through Seed Certification. The best way to do this is online

Can test results be converted from one system to another, such as AOSA to AOSA/EC (OECD)?

Yes, conversions can save time and money for our customers. Crop and weed exams can be converted to sod quality (SQ) for most species, UGS, or Canada exams in most cases. For example, a crop and weed exam on Tall fescue can be converted to SQ, UGS or a Canada exam with no additional testing required. SQ can be converted to UGS or Crop and Weed certificates in most cases. See the price list for conversion pricing information.

Conversion Information for Common Crops
Paperwork only - no additional testing required
Tall fescue Ryegrass/Bentgrass
Kentucky bluegrass Tall fescue
Orchardgrass Rough bluegrass
Chewings and Red fescue All fine fescues
Additional testing required for conversion
Ryegrass: add'l 10 grams Kentucky bluegrass: add'l 5 grams
Rough bluegrass: add'l 0.5 grams  

Sheep and Hard fescue: add'l 5 grams


Bentgrass: add'l 5 grams  


Can I pay my bill with a credit card?

Yes. You can pay by credit card through the OSCS Online Services website. Instructions for accessing that system and paying your invoice online can be found on this customer guide.

How can I tell if my bill is from the Seed Lab or Seed Certification?

At the top of the invoice, either Seed Laboratory or Seed Certification is shown in bold letters. 

Other Questions

Can I see the weed seeds or inert in my sample?

If you come to the lab, we can show you any kind of contaminant found in your sample. Please schedule this ahead of time. If you cannot come, we can take a digital picture, side by side with the crop seed, and e-mail it to you. There is a fee for this service.

Can I come watch my seed being tested?

To ensure that our analysts are not under any undue pressure, we do not generally permit customers to watch their own samples being tested. If you have any questions, please contact the Laboratory Manager to arrange a visit after the sample has been tested.