Abstract
A precise, reproducible, and sensitive serum neutralization test was developed to estimate Venezuelan equine encephalomyelitis neutralizing antibody activity within 24 hr. The test depends on the interactions of virus with antiviral globulins and of the resultant complexes with anti-gamma globulin (IgG) antibodies. The 50% serum neutralizing dilutions were calculated from the reduction of fluorescent cells in McCoy cell monolayers resulting from the neutralization of infective virus by antibody. In comparative estimates of the neutralizing activity of human and monkey antisera, the sensitivity of the serum neutralization anti-IgG test was several hundredfold greater than that of the conventional serum neutralization test in mice.