“Plasma is a yellow liquid that makes up part of the blood, responsible for carrying antibodies around the body.

Dedicated donation centres in Birmingham, Reading and Twickenham have specialist machines which separate red blood cells and haemoglobins and retain plasma.

The substance is then used to make immunoglobulins, which strengthen and stabilise the immune system.

NHS Blood and Transplant said medicines made from plasma treated more than 50 immune disorder diseases, but said thousands more donors were needed.”

From BBC.