The effect of homogenising tissues either before or after storage on the isolation of Chlamydia trachomatis

To determine whether freezing before homogenisation or the reverse procedure was the best way of achieving maximal recovery of chlamydiae from solid tissues, specimens from mice infected experimentally with Chlamydia trachomatis were used. For 10 of 12 mice, three-fold to over fifty-fold more chlamydiae were isolated from portions of spleens which were homogenised before freezing in liquid nitrogen than from those which were homogenised after being stored frozen. The value of homogenising small strips of infected genital tissue before freezing was less apparent. Nevertheless, if this was undertaken, the number of chlamydiae recovered from the tissues of four of 10 mice was three-fold to seven-fold more than if the tissues were homogenised after freezing.