Improved method for isolation and growth of Chlamydia trachomatis in McCoy cells treated with cycloheximide using polyethylene glycol.

The sensitivity of non-replicating McCoy cells pretreated with polyethylene glycol for the isolation of Chlamydia trachomatis from clinical specimens and for the growth of a laboratory strain was compared with the sensitivity of untreated non-replicating cell cultures. The concentration of polyethylene glycol in different solutions and the time of addition to the cell culture medium were critical. A concentration of 35% polyethylene glycol in barbitone added to the cell culture growth medium either immediately before or immediately after infection with chlamydia increased the number of inclusions detected. The rate of isolation obtained from clinical specimens was also increased when cell cultures treated with polyethylene glycol were used.