While our blood is iron based, some animals have copper based blood turning it blue. It is called hemocyanin. Human blood is red because of the presence of hemoglobin. Lobsters, spiders, molluscs, arthropods and other animals can and do in fact have blue blood. Humans do not. Neither rhesus negative nor rhesus positive people. The claim that rhesus negative blood is copper based and that the term blue blood originates from copper based blood in rhesus negatives is a complete fabrication. There are various speculations as to where the term “blue blood” origins and again: This is something man-made in terms of coining a phrase vs. science as it is. A popular explanation for the term is that the royals … Continue reading “Blue Blood”: Is Rhesus Negative Blood Copper Based?