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One Cord, Many Possibilities · Research

Study Shows Cord Blood Still Viable After Nearly 30 Years

A German cord blood bank thawed units frozen for up to 29 years. About 9 in 10 cells were still alive.

November 13, 2026 3 min read StemCyte Editorial Team
In use today: stored cord blood in transplants This study looks at cord blood units like the ones used in transplants today, after decades in storage.
실험실 및 동물인체 시험현재 사용 중
Journal
Stem Cells Translational Medicine
Published
November 2023
Cord blood bank
José Carreras, Germany
Longest storage tested
29 years

Every parent who banks cord blood eventually wonders the same thing: if my child ever needs these cells, will they still work? A study from one of the world’s longest-running cord blood banks gives one of the clearest answers so far.

What the researchers looked at

The José Carreras Cord Blood Bank in Düsseldorf, Germany, began banking cord blood in 1992. Its team, which included Eliane Gluckman, the physician who performed the world’s first cord blood transplant in 1988, looked back at three decades of the bank’s own records in two ways.

  • Lab testing. They thawed samples of their oldest units, frozen for up to 29 years, and measured how many cells were still alive and whether the cells could still grow.
  • Transplant follow-up. They tracked how the 1,476 units they had released to unrelated transplant patients performed, and whether units stored longer took hold more slowly.

What they found

Cells alive after 29 years frozen

Units frozen whole, without processing. Each dot is 1% of cells.

89%of total nucleated cells were still alive after thawing
Alive after thawingNot alive
  • The cells were still alive. In units frozen for 29 years, about 89% of total nucleated cells were still alive after thawing. So were about 91% of the blood-forming stem cells, the cells that rebuild a patient's blood after a transplant.
  • They could still grow. Placed in a lab dish for two weeks, the thawed cells still formed new colonies, a sign they could still do their job.
  • Storage time didn't hold transplants back. Engraftment is when transplanted cells take hold and start making new blood. In the authors' words, "the time of cryopreservation has no significant detrimental effect on engraftment after transplantation."

What it means

Cord blood is collected once, at birth, and may not be needed for decades. This study shows that properly frozen cord blood cells can stay alive and working for nearly 30 years. The bank now stands behind its longest-stored type of unit for 29 years.

That 29-year mark isn’t an expiration date. It is the longest this bank has been able to test so far, and the bank extends it as its oldest units get older and more results come in.

StemCyte’s part

2001A StemCyte unit is collected in Orange County, CA
2025It ships for transplant in France

StemCyte has banked cord blood for more than 25 years, and every unit in our care is stored with continuous temperature monitoring. In that time, we have shipped cord blood units to transplant centers in the United States and abroad, including units that had been frozen for more than two decades.

Our public and private banks have been AABB accredited since 2002 and FACT accredited since 2006. FACT standards also shaped the German bank’s stability testing in this study.

Read the original studyLiedtke S, Többen S, Gressmann H, Meyer A, Verde PE, Gluckman E, Kogler G. Long-term stability of cord blood units after 29 years of cryopreservation: follow-up data from the José Carreras Cord Blood Bank. Stem Cells Transl Med. 2024;13(1):30–42. doi:10.1093/stcltm/szad071
더 읽어보기: One Cord, Many Possibilities One Cord, Many Possibilities In use today

Fourteen years of national data show the safety record of donated cord blood

A 14-year national review of 13,358 donated cord blood units from 27 public banks, including StemCyte’s. 94% had no reported incident.

Questions about how your baby's cord blood is stored?

Talk with your doctor, and ask us how StemCyte collects, freezes and monitors your baby's cord blood.

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