The main analytical pitfalls in insulin measurement in serum are related to (a) hemolysis, (b) circulating anti-insulin autoantibodies, and, for the past few years, (c) the reactivity (or lack of reactivity) of rapid- or long-acting pharmacological insulin analogs in sera (1 ). Hemolyzed samples contain an insulin-degrading enzyme and should not be analyzed unless they can be handled at 4
