A comparative study of agar overlay and standard tissue culture methods for isolation of enteroviruses.

A study was made of the isolation of enteroviruses from 62 cerebrospinal fluids and 141 autopsy specimens with standard fluid monolayer tissue culture methods and tissue cultures under agar overlay with and without added MgCl2 (0.025M). Sixteen virus isolations were made only by the overlay method, two only by the standard technique, and six by both procedures. Additional studies were carried out on 975 diagnostic specimens of various types with standard tissue culture methods and with primary rhesus kidney cells under agar overlay containing 0.025M MgCl2. Seventeen virus isolations were made only by the overlay procedure, 20 only by the standard tissue culture method, and 75 by both techniques. Since there were instances in which either the agar overlay or the standard method alone succeeded in isolating a virus, use of both types of procedures would be desirable to isolate as many enteroviruses as possible from clinical specimens.