Table 3 Comparison of the detection capacities of the broad‐range real‐time PCR for Chlamydia with two commercial kits on 100 clinical samples obtained from children with trachoma.

Technique	Amplicor*	Artus*	Broad‐range assay
Total tested	100	100	100
Negative samples	95	95	89
Positive samples	5†	5†	11†
	+	+ (20)	+ (23)
	+	+ (28)	+ (24)
	+	+ (32)	+ (33)
(Ct) values for the	+	+ (36)	+ (35)
samples testing	+	+ (29)	+ (31)
Positive by real‐time PCR	N	N (>40)‡	+ (33)‡ #
	N	N (>40)‡	+ (37)‡¶
	N	N (>40)‡	+ (33)‡¶
	N	N (>40)‡	+ (30)‡¶
	N	N (>40)‡	+ (32)‡¶
	N	N (>40)‡	+ (31)‡¶

N: negative; +: positive.

*According to manufacturer's instructions.

†The five samples detected as positive by Amplicor were detected positive by the other two methods. Reaction volumes were 50, 20 and 50 μl, respectively.

‡The signals obtained for the internal controls (plasmid supplied in the Artus Abbott kit and amplified simultaneously in the same reaction tube or seal herpes virus for the broad‐range assay amplified separately) showed no inhibition. The yield of recovery of DNA after elution was acceptable (Ct values of the controls for each sample compared with the Ct obtained with the blanks and controls were never delayed by more than 1.5 cycles).

¶The second derivative of the plots indicates that the peaks are relevant (positive).