Beijing Cancer Hospital confirmed to the Global Times Tuesday that it has recruited enough female college student volunteers to provide virgin blood for medical research and that the collection of blood samples has been completed.

The hospital's call for virgin blood stirred controversy after it was posted online last week.

The recruitment had been finished by Sunday, Guan Jiuping, director with the hospital's Party committee office, told the Global Times Tuesday.

A staff member at the hospital told The Beijing News Monday that they had recruited 100 volunteers by Sunday. On that Sunday alone, dozens of volunteers donated blood, said the staffer, adding that they would exclude some unqualified samples based on statistics.

The hospital's genetic research laboratory posted a notice on online forums for Peking University and Beijing Normal University on September 11, saying it was carrying out research on an HPV serum antibody in a bid to explore cancer prevention and cures related to HPV.

It planned to recruit 100 female volunteers to provide 3 - 5 milliliters of blood each. The candidates should be aged from 18 to 24, be virgins and in good physical condition. Each of them were to be paid 150 yuan ($24.51) after their donation was completed, said the notice.

However, the notice caused a heated discussion online. Some Net users suspected that the research was sensitive as it was related to people's virginity. Some criticized the medical institution's odd focus while others countered that almost every medical project has a specific target group and were willing to support the project, People's Daily Online reported on Tuesday.

Just one day later, the notice was deleted. Guan said the reason was that the hospital had found enough volunteers.

Virgin blood will be used in research on causes leading to esophageal cancer in areas where cancer rates are higher than the norm. The epithelial cells of esophagus are similar to those of the cervix, said the employee, adding that the cause of cervical cancer is relevant to HPV.

"We want to know if the cause of esophageal cancer is related to HPV. Therefore, we need to collect female blood that is not infected by HPV," said the staffer.

A research fellow on HPV biological vaccines with Peking Union Medical College said a HPV serum antibody needs people who have no HPV infections as a reference group, with sex being the main way to contract an HPV virus. Among female virgins aged 18 to 24, the possibility of being infected is much smaller, the research fellow told The Beijing News.

Recruiting volunteers in campus forums is easily conducted at the start of each new semester. 

"Our hospital has recruited volunteers through our official website in a long time but the recruitment this time had special requirements for the volunteers. Since most of our website readers are patients, we decided to publish the notice on campus forums," the staffer said.