Okay so I was always taught to use the rule of 3, 3 positive reactions and 3 negative reactions for peforming an antibody ID. I was also taught to always use homozygous positive and negative cells whenever possible. Sometimes of course it is not due to low incident/high incident antigens. I do know you need to use a homozygous cell when performing "rule outs". What is everyone else's practices and thoughts as I need to clarify our current antibody identification policy. Thanks in advance.