A teacher from Northampton hopes a complete stranger might be able to save her mother's life.
Despite successfully fighting leukaemia three years ago, Jackie Smith has been told her cancer has returned and she now needs an urgent bone marrow transplant.
Searches for a suitable donor have so far turned up blank in both Europe and America.
Now, Mrs Smith's daughter Kathryn Murphy, the assistant headteacher at Mereway Community College, hopes somebody from Northampton may be able to help.
She said: "Mum fought this successfully three years ago but unfortunately the cancer has returned. To beat the disease she urgently needs a bone marrow transplant.
"She has a loving family, who can't imagine life without her. She has a husband, a mother, two daughters and three wonderful grandchildren who are relying on help from a stranger.
"Without a bone marrow transplant we know she may not be around to see her grandchildren grow up."
To help trace a suitable donor, Mrs Murphy has organised a special event at her school.
During the session, people will be told what it means to join the donor register and be asked to give a small sample of blood.
She said she hoped the session would show people the true implications of becoming a bone marrow donor, adding: "People are under a false impression that giving bone marrow is a long and painful process, but you can now do it without the need for a general anaesthetic or a stay in hospital."
She was backed by Debby Jepps from the Anthony Nolan Trust, which helps people find bone marrow donors.
She said: "Our register can never be big enough, we're always in need of more donors. It's so important that if you're eligible to join the register, to think seriously about it. The more people we have registering, the more chance we have of finding those life-saving matches for patients."
The Mereway Community College session will be held from 3.30pm until 7pm on Tuesday, March 25.