Original Article

Ann Lab Med 2017; 37(2): 124-128

Published online March 1, 2017

Copyright © Korean Society for Laboratory Medicine.

Long-Term Quality Control Program Plan for Cord Blood Banks in Korea: A Pilot Study for Cryopreservation Stability

Soo Hyun Seo, M.D.1,2,3,*, Sue Shin, M.D.1,2,3,*, Eun Youn Roh, M.D.1,2,3, Eun Young Song, M.D.1, Sohee Oh, Ph.D.4, Byoung Jae Kim, M.D.5, and Jong Hyun Yoon, M.D.1,2,3

Department of Laboratory Medicine1, Seoul National University College of Medicine; Department of Laboratory Medicine2, Boramae Hospital; Seoul Metropolitan Government Public Cord Blood Bank (Allcord)3; Department of Biostatics4, Boramae Hospital; Department of Obstetrics and Gynecology5, Boramae Hospital, Seoul, Korea

Correspondence to: Jong Hyun Yoon
Department of Laboratory Medicine, Seoul National University Boramae Hospital 20 Boramae-ro 5 gil, Dongjak-gu, Seoul 07061, Korea
Tel: +82-2-870-2601 Fax: +82-2-870-2632 E-mail:
*These authors equally contributed to the study.

Received: March 2, 2016; Revised: August 9, 2016; Accepted: November 17, 2016

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background: Maintaining the quality of cryopreserved cord blood is crucial. In this pilot study, we describe the results of the internal quality control program for a cord blood bank thus far.
Methods: Donated cord blood units unsuitable for transplantation were selected for internal quality control once a month. One unit of cord blood, aliquoted into 21 capillaries, was cryopreserved and thawed annually to analyze the total nucleated cell count, CD34+ cell count, cell viability test, and colony-forming units assay.
Results: No significant differences in the variables (total nucleated cell count, cell viability, CD34+ cell count) were observed between samples cryopreserved for one and two years. Upon comparing the variables before cryopreservation and post thawing with the capillaries of one year of storage, cell viability and CD34+ cell counts decreased significantly. The use of cord blood samples in capillaries, which can be easily stored for a long period, was similar to the methods used for testing segments attached to the cord blood unit.
Conclusions: The results of this study may be useful for determining the period during which the quality of cryopreserved cord blood units used for transplantation is maintained.

Keywords: Umbilical cord blood, Internal quality control, Cryopreservation, Capillaries