Human stem cells produced at Kyoto University. (Shinya Yamanaka/Associated Press)

Canadian Blood Services is trying to encourage more people from ethnic communities to register as stem cell and marrow donors.

The donations are used to treat patients with blood-related diseases such as leukemia and aplastic anemia.

Donors and recipients must match according to the compatibility of inherited genetic markers, according to Canadian Blood Services, and the best match is usually found within the recipient's ethnic community.

In a bid to encourage more South Asian donors, Canadian Blood Services held a drive at a mosque in northeast Calgary on Saturday.

Volunteers at the Akram Jomaa Islamic Centre showed people how to sign on to the donor registry and explained the importance of being a donor.

Nazir Hashan knows first-hand how difficult finding a donor can be.

"My son, he had acute lymphoblastic leukemia and the donors are very underrepresented in the ethnic community," he said.

"He's in remission [now], but there are so many other people in the ethnic community who cannot find a stem cell match or a bone marrow match, so that's why the Muslim community decided to have this event here."

Canadian Blood Services says drives like the one held in Calgary are key to expanding the donor base.

Anwar Terrabain, a member of the mosque, decided to register on the spur of the moment.

"I actually came to pray, I didn't know it was here, and when I saw that they were here I thought it would be a good thing to register for. I think it's our obligation, our duty as citizens, to help," he said.

Canadian Blood Services says donors of all backgrounds are needed, and ethnicity is not the sole determining factor in a good match.

But they say donors from underrepresented ethnic minorities are in the biggest demand.