Standardization of Vipera ammodytes antiserum.

The determination of the activity of viper antiserum in terms of the effective dose against 1 minimum lethal dose (MLD) of venom often leads to results which are not very reproducible. The present study concerns the preparation of a standard Vipera ammodytes antiserum and the choice of a suitable venom test dose. Portions of purified, concentrated antiserum were distributed into vacuum-sealed ampoules for use as a standard, and the amounts of this standard antiserum needed to neutralize various amounts of ammodytes venom were determined. The antivenin unit (AU) was fixed at 1.90 mg; 1 AU is the amount of standard serum required to protect 50% of white mice weighing 18 g against 0.05 mg (5 MLD) of venom. The use of the standard antiserum for titration of crude antisera in terms of this AU is described.