One of the concerns I came across with the ProVue is the extended crossmatch. If you use only the IgG card in doing your crossmatch, because the package insert does not claim that the card is capable of identifying IgM, a laboratory was cited for not ruling out ABO incompatibility. In other words, we have a policy to do an extended crossmatch for all positive antibody screens, we do not perform Antibody ID. However, using the ProVue means we have to perform both a Buffer Gel (IS) and the IgG card (extended).