Prevent donated blood being sold for profit

Last year when i went to give a pint of blood i was asked as always if i had any questions.On this occasion i said "Yes.How do private hospitals get their blood?".i was told that they get it from the NBS (National Blood Service) which supplies both NHS and private hospitals,at the same price.The price is the cost price of collecting,testing,processing & distributing the blood.i emailed the National Blood Service who said that they "are not involved in determining the charges made by private hospitals to their patients" but expressed no view on whether its right that private hospitals can choose what price they sell blood at..So i wrote to my MP who later sent me a reply he received from Dawn Primarolo ,from the Department Of Health saying that the Government "are not involved in determining the charges made by private hospitals to their patients".My MP wrote again but the Department had nothing further to add .
If you think that private hospitals should be prevented from selling donated blood at a profit please sign the petition :-

 http://petitions.number10.gov.uk/Blood-donors/