Because of the difficulty experienced by many laboratories in isolating the meningococcus from the cerebrospinal fluid from patients with epidemic meningitis and in keeping the strains alive without frequent transplanting, it should be of help to describe the simple method of using dextrose semisolid agar with which the Meningitis Division of the New York City Health Department has been having satisfactory results.
Good results are obtained not only with fluids withdrawn before the first dose of serum has been given but also with fluids from patients when serum treatment has already been instituted and from fluids which have been delayed from twenty-four to forty-eight hours in reaching the laboratory.
The routine, which is the same for all cloudy or hazy fluids, regardless of the etiology, is as follows:
All specimens received are centrifugated at high speed for from five to ten minutes, regardless of the degree of turbidity. The supernatant