We all invariably encounter unexpected antibodies in the blood bank laboratory. In some cases, in addition to a positive antibody screen, an ABO discrepancy is detected. The blood bank technologist must then investigate to determine whether the cause of the positive antibody screen is linked to the ABO discrepancy. Sometimes they are linked, and sometimes they are not. This audioconference will help provide the tools and approaches to helping determine whether a linkage exists and provide problem-solving tools that should help identify unexpected antibodies, sources of ABO discrepancies due to unexpected antibodies, and to assist in streamlining the approach towards both types of problems. This audioconference will include lecture material in addition to supplementary case studies.