Stability of varicella-zoster virus and herpes simplex virus IgG monoclonal antibodies.

The stability of 3 monoclonal antibodies was analyzed at various temperatures and freeze/thaw cycles. Two varicella-zoster virus (VZV) IgGs (mAb 4F9 and mAb g62) and 1 herpes simplex virus 1 (HSV-1 mAb 1D4) were selected for these studies. IgGs were either incubated at various temperatures (25 degrees C, 37 degrees C, 45 degrees C, and 60 degrees C) for different periods of time (0 to 9 weeks) or processed for several freeze/thaw cycles. The reactivities of mAbs 4F9 (IgG1), g62 (IgG1) and 1D4 (IgG2b) were tested by indirect immunofluorescence assay (IFA). The results indicated that: (1) all three mAbs were stable at 25 degrees C and 37 degrees C for 9 weeks; (2) although the reactivities of mAbs g62 and 1D4 were diminished after 5 weeks, mAb 4F9 was stable at 45 degrees C for 9 weeks; and (3) all 3 IgGs lost reactivity after overnight incubation at 60 degrees C. In addition, the results showed that the reactivity of mAbs 4F9, g62 and 1D4 was not diminished after 12 freeze/thaw cycles.