Roughly 1 pint is given during a donation. ??? A healthy donor may donate red blood cells every 56 days, or double red cells every 112 days. ??? A healthy donor may donate platelets as few as seven days apart, but a maximum of 24 times a year. ??? All donated blood is tested for HIV, hepatitis B and C, syphilis and other infectious diseases before it can be released to hospitals. ??? Information g