Members of the China RH Union, an NGO that provides assistance to people with rhesus negative-type blood, share a common desire. They hope that more carriers will be found and make it as easy for them to receive transfusions as people with more-common blood types.

The problem is that most people don't know whether they are rhesus positive or negative, even though the suffix is added to every member of the ABO blood group. Tests are only conducted during voluntary premarital checkups and pregnancy examinations in big cities, or when people are donating blood or need a transfusion.

Wang Yong, head of the China RH Union, said the NGO has raised nearly 100,000 yuan ($14,500), and later this year it will start a campaign to encourage every citizen to take a test to identify their blood group.

"We've reached cooperation agreements with two public hospitals in Beijing and another in Langfang, Hebei province. We will publicly advertise that we can provide 1,000 free blood tests," he said.

The volunteers also want to see improvements to the allocation system in blood centers to ensure that donated blood is used efficiently.

According to Wang, if a volunteer donates blood to specific patient but it isn't used, the only chance of stopping it going to waste is if another patient in the same hospital has the same blood type and needs a transfusion within 35 days of donation. The blood is not sent to a blood center and it cannot be used by other hospitals.

"Sometimes we make great efforts to persuade volunteers to donate blood, but if it isn't used they may be less willing to donate a second time," he said.

"Every time I see media reports of people swarming to blood centers to donate after a disaster, I realize that our society doesn't lack a benevolent spirit. However, we definitely need a better system of blood donation and management."