Malcolm, We have done a screen using pre-warmed plasma, cells, anti-IgG cards, anti-IgG reagent, C3D reagent, all nicely warmed first then mixed and warmed again. All turn out negative. Early AM today he got 2 units of blood with a blood warmer with no complications. Both the C3b/C3D and anti-IgG were positive at RT but negative pre-warmed. I just wanted to hear that a pre-warmed DAT is OK to do. Thank You