Beijing has the largest proportion of residents donating blood among cities across the country, said Beijing Health Bureau on Thursday.

According to the bureau, 1.9 percent of the city's residents have donated blood; about 121 tons of blood were donated in the city in 2012, of which 80 percent was collected by blood collection buses on the street.

The city is also spending "a large amount" of money to do RNA tests for blood samples collected so that HIV infection can be detected within 11 days, reducing the risk of blood collected from people infected with the virus to be used in surgeries.

Liu Jiang, director of Beijing's blood donation office, which manages blood donation operations in the city, said in June 2012 that the city has four blood stations, but only the Beijing Red Cross Blood Center was able to do RNA tests.

The situation is changing.

A staff member surnamed Zhong in the blood station in Tongzhou, one of the four blood stations, told China Daily that the blood station’s RNA test laboratory passed the assessment by the city’s health bureau on June 7, thus it will be able to test all the blood samples it collects in the near future.