A constituent wrote to me recently about blood - or more specifically, about blood cancer.

The letter was about the work of Anthony Nolan, a charity that supports the NHS when it treats patients requiring blood replacement.

I recently once again met representatives of this remarkable organisation about whom I have written previously in this column and was reminded just how impressive its contribution is. 

Anthony Nolan has gradually and painstakingly established a register containing genetic data for the blood of hundreds of thousands of volunteers who have come forward, had their genes tested and committed to provide blood or bone marrow from which stem cells can be extracted to enable the NHS to provide replacement blood.

The power of this national database run by the charity here in the UK is multiplied many times over by the use of modern communications technology to enable full exchange of information with similar databases in other countries, thereby providing access to a vastly greater array of genetic structures with a correspondingly higher chance of providing a close enough match for a particular patient. 

All of this is based ultimately on the willingness of volunteers between the ages of 16 and 30 to join the register and to make an advance commitment to donate when lives are at stake. I hope that anyone reading this column who is either aged between 16 and 30 themselves and is willing to join the register or knows of someone of the relevant age who might be willing to join the register will consider taking the necessary steps. 

Anthony Nolan is to be found at www.anthonynolan.org