SOME SO-CALLED BLOOD BROKERS in Nanning, capital of South China's Guangxi Zhuang autonomous region, have reportedly established an underground blood exchange network. Beijing News commented on Wednesday:

It is no secret that blood transfusions play a vital role in modern healthcare, which explains why the medical authorities have imposed restrictions on the use and storage of blood donations.

As of now, all the blood used for transfusions should come from official blood centers. However, this to some extent limits the blood supply, because blood can only be stored for a short time and thus cannot be stored in large quantities.