The effect of 2-mercaptoethanol on IgM and IgG antibody activity

Abstract

The effect of reduction by 2-mercaptoethanol (2-ME) on antibody activity was studied in antisera with high anf low IgG concentrations. Sera obtained from B10.LP nu/nu mice during a primary response against a rat PVG/c skin graft contained only 2-ME sensitive antibodies. However, when analyzed on sucrose gradients, IgG as well as IgM antibody activity was present. After raising the low serum IgG concentration (0.3–0.7 mg/ml) of these sera by additional of normal mouse serum (5.1 mg IgG/ml), 2-ME resistant antibodies became detactable. Hyperimmune C57BL6 anti PVG/c lymphocyte serum with a high IgG concentration (20.2 mg/ml) and antibody activity predominatly located in the IgG class was not affected by 2-ME treatment. These data show that IgG antibodies, although less susceptible to reduction than IgM antibodies, are not resistant to this treatment. At high IgG concentrations the proportion of inactivated IgG with specific antibody will be negligible but a low IgG concentrations the use of this method leads to serious underestimation of IgG antibody activity.