Wu Zuqin, 32, from Wenzhou, east China's Zhejiang province, handed the 217 ml-suspension of his hematopoietic stem cells to a representative from South Korea Tuesday at the Air Force General Hospital of the PLA in Beijing. Hours later, his stem cells would be transported to Seoul and be transplanted to a 47-year-old South Korean woman who had been diagnosed with multiple myeloma.

Wu has been an unpaid blood donor since 2008. In 2011, his data was recorded by the China Marrow Donor Program (CMDP); in 2013, he was told that there was a match between his stem cells and those of a South Korean patient in urgent need of a transplant.

"When my parents first learned of my decision to donate stem cells, they were kind of worried. But I explained all the details I was about to go through and they threw their support to it," said Wu.

"To use my own stem cells to save another life, it's a very sacred thing," he added.

Wu is a doctor at a medical service center in Longwan District, Wenzhou. His wife is a shop owner and they have a 7-year-old son.

It is reported that there are over 1.8 million volunteers registered with the CMDP and Wu is the 4124th donor. He is also the 142th donor whose stem cells are transplanted to overseas patients. Such matches are extremely rare, with the match rate being under ten thousandth or even hundred thousandth.