Summary
By suspending a 16-hour meningococcus culture in sterile fresb guinea pig's serum, diluted to four times its volume, and injecting this suspension intraperitoneally into white mice, a regular virulence can be demonstrated.
If the amount of serum necessary to protect against one M.L.D. of culture is considered as a unit, a rational and uniform method of standardizing antimeningococcus serum can be obtained.
A dosage similar to that of antitoxic serum would be possible by such a method of standardization.
The protection test parallels the extent of immunization more nearly than agglutination or complement fixation tests.
The protection test is specific, differentiating strains of meningococci as well as the gonococcus.
The polyvalency of an antimeningococcus serum is of extreme importance.
