Updated

Gov. Mark Dayton on Wednesday had an injection with a four-inch needle at the Mayo Clinic on Wednesday to help heal a hobbled hip.

"He said he tried to persuade Mayo to let him take the needle home as a souvenir, but was told its disappearance would breach their protocol," Dayton Deputy Chief of Staff Bob Hume said. Dayton once planned to go to medical school but ended up going in a different direction.

The injection of platelet rich plasma, made from his own blood, was intended to heal a hip muscle injury he sustained over the summer. The procedure, which has become popular among athletes, took 80 minutes. The governor is paying for the treatment out-of-pocket. The cost was not immediately available.

Dayton spokesman Matt Swenson said the governor was in good spirits and would head back to his St. Paul residence Wednesday afternoon. The governor's office said he is not on prescription medication.

"Once again, the people at Mayo showed why they are the world's best. We are very fortunate to have such an amazing resource here in Minnesota," Hume reported Dayton said. The governor also went to Mayo last year for back surgery.

Dayton was a strong backer of the Mayo Clinic and Rochester's push for $585 million in state and local tax support for the city's new Destination Medical Center project.

The governor, 66, has said his ailments will not stop him from running for re-election.