A transfusion in action
Blood transfusion is the process of transferring blood or blood-based products from one person into the circulatory system of another. Blood transfusions can be life-saving in some situations.
Wolverine performed blood transfusions to try to use his mutant healing power to save others. However, it only worked twice.
A transfusion kit
When Leech was close to death, Storm and Jubilee convinced Logan to perform a transfusion even though he was unsure if it would help at all. It did help and Leech was fine.