The painting is a protest against UK rules which ban men from donating blood within 12 months of having sex with another man.
This is what a painting made from blood looks like.
Conor Collins
The painting was commissioned by campaign group Freedom to Donate, who unveiled it at an event at a reception at the Houses of Parliament on Monday.
Artist Conor Collins told BuzzFeed News that almost all the blood is from medical professionals who are unable donate blood, because of their sexuality.
"With the exception of one person, all the blood in the painting is from GPs, surgeons, nurses. They're all medical professionals who, because of who they are, can't donate blood," he said.
"One of them was a heart surgeon and you literally trust him to open you up and hold your heart in his hands and yet we apparently, according to the law, don't trust him to donate blood.
"It was surprisingly easy to get the blood. Once I started telling people about the piece and the protest we were making, they were instantly eager to help."
Men who have had sex with another man in the last 12 months can't give blood, according to NHS guidelines.
Asked why he chose Turing – who was gay – for the painting, Collins said there were parallels to his sacrifices and persecution.
"The first thing is that he anonymously through his actions saved the lives potentially of millions and millions of people," he said.
"And when you donate you anonymously save the life of someone you've never met and who you'll maybe never meet.
"The second thing is that Alan Turing, despite all the actions and great things he did, if he was alive today he wouldn't be allowed to donate blood either."