It’s as the NHS issues a warning that supplies of this rare blood type are at risk of running low.
There are more than 2,800 B negative donors in the region who are eligible to give blood right now according to the NHS.
Only 2% of the population have this blood type.
Patients with the B negative blood type can only receive B negative or O negative blood.
The nearest blood and plasma donor centre for people in South West London is in London Road in Twickenham.