It's normal for a vampire to crave the blood of a virgin, but not a respected research hospital.
So when the Peking University Cancer Hospital in China put out a request for ages 18 to 24, some people thought it was bloody awful, according to AFP.
"Male virgins are not needed, just females, how is this science?" posted one highly-cited user of a Chinese social media service similar to Twitter.
Hospital official spokeswoman Guan Jiuping insisted the blood wasn't for some bizarre human sacrifice ritual. It seems that researchers were doing studies on the human papilloma virus (HPV), which is usually transmitted through sexual contact.
"It's in line with international practice to collect female virgins' blood samples, which serve as negative control substances in HPV research, given that the risk of contracting HPV is low among women who have never had sex," Guan said, according to China Daily. "Too much attention to sensitive words like 'virgin' and 'sex' is not necessary in this context."
Researchers said virgin blood is helpful because risk for the virus is low among women who have not had sex, the Metro reported.
So far, 50 self-proclaimed virgins have donated their blood to science, IBTimes.co.uk reported. However, the number of actual virgins may be smaller, because the hospital is taking all the donors at their word.