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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Agricultural Genetic Resources Preservation Research » Docs » Seed » Seed Storage Protocols

Storage vault.

SOP 6.1 Packaging & Storage for NPGS standard -18C backup, PVP, JPR, GMO (PDF)

SOP 6.5 Cryogenic Seed Storage (PDF)

SOP 12.2 Viability Testing (PDF)

SOP 12.4 Monitor Testing (PDF)


Seed in Base, PVP, or Plant Registration Collections

  1. Seed is received via U.S. Postal Service or an expedited mail service.
  2. Seed is placed at 5°C until unpackaged, logged in and inventoried (1-5 days).
  3. The moisture content of seed is adjusted at 5°C and 25% relative humidity for 3-4 weeks.
  4. Seed may be temporarily stored at -18°C for up to 4 months awaiting an initial viability assessment using standard germination tests.
  5. Seed quality is assessed through germination tests that use Association of Official Seed Analysts rules as a guideline. 
    • Germination procedures are specific to each species.
    • Under most circumstances, four reps of 50 seed are scored for initial germination assessments.
    • For seed considered for long-term liquid nitrogen storage, two of the four reps are exposed to liquid nitrogen for 24 hrs prior to germination.
  6. Germination data are entered into GRIN.
  7. The seed sample is weighed to determine seed number. 
  8. The seed is packaged in a heat-sealable aluminum foil laminate bag.
  9. The package is labeled with bar code identity and location labels.
  10. Data on seed weight, seed number and storage location are entered into GRIN.
  11. The packaged seed is placed into NCGRP's -18°C storage vault or liquid nitrogen for long-term storage.

Seed for Safety Backup (black-box) Storage

Seeds receive above steps 1-2 and 9-11 (no data on seed weight or number) when the owner prepackaged the seed in foil-laminate bags.  Seeds receive additional steps 3 and 8 if moisture adjustment and moisture proof packaging were not provided by the owner.