Reduced detection of Chlamydia trachomatis by the ligase chain reaction assay due to suboptimal storage of urine

Detection of Chlamydia trachomatis by the ligase chain reaction assay was a ssessed in urine samples that had been stored at VC and at ambient temperat ure for 6-10 days before testing. Six of 67 (9%) ligase chain reaction-posi tive urine samples stored at 4 degreesC and 5 of 29 (17%) stored at ambient temperature became negative, a difference that is not statistically signif icant. Most of the urine samples that were negative after storage contained a small number of chlamydial elementary bodies, and almost three-quarters of them were from women. Optimal pretest storage conditions for urine sampl es should be maintained if the maximum benefit is to be obtained from this highly sensitive assay.