This product has been prepared from sera of non-immunized rabbits. The immunoglobulin fraction has been isolated in the same way as the immunoglobulin fraction of Dako rabbit antibodies. In addition, the product has been passed through a column containing immobilized human plasma proteins. This reduces the non-specific background and makes it particularly well-suited as a negative control for Dako solid-phase absorbed rabbit antibodies. Especially when the primary antibody is used for immunohistochemistry at a relatively high concentration, above 0.1 g/L, this product should be preferred to Dako Rabbit Immunoglobulin Fraction (Normal). The protein concentration of this product is 15 g/L.