A vial of blood drawn from John Paul II will serve as a relic during the late pontiff's upcoming beatification Mass in Rome on May 1.

The Vatican announced on April 26 that the relic will to be presented to Pope Benedict XVI and exposed for veneration during the Mass in St. Peter’s Square this coming Sunday. The vial will then be stored in a shrine by the Office of Liturgical Celebrations of the Supreme Pontiff, along with other relics.

Four vials of blood were drawn shortly before John Paul II's death on April 2, 2005 by a personal physician, in case of the need for a transfusion. The Vatican explained in a April 26 statement that the blood in the vials is in a liquid state due to an anticoagulant substance which was present in the tubes at the time of collection.

One vial will remain in the custody of the Daughters of Charity of St. Vincent de Paul at the Vatican-owned Bambino Gesu Hospital in Rome.

The remaining two vials are now in the possession of Cardinal Stanislaw Dziwisz, the Archbishop of Krakow and former secretary of John Paul II and will be installed in a Polish church soon after the beatification.

Piotr Sionko, the spokesman for the John Paul II Center in Krakow, said the vials will be encased in crystal and built into the altar of a church in the city. The church, which is still under construction in Krakow’s Lagiewniki district, will open sometime after the May 1 beatification. The building is part of a planned center devoted to cultivating the memory and teachings of the late Pope, a former archbishop of Krakow.

Sionko said that Cardinal Dziwisz proposed the idea of using the blood as a relic, saying that the cardinal “is of the opinion that this is the most precious relic of John Paul II and should be the focal point of the church.”

As part of Catholic tradition, the veneration of relics is a practice that recognizes the God-given sanctity of a saint or blessed and anticipates his or her bodily resurrection.