Internally Controlled, Generic Real-Time PCR for Quantification and Multiplex Real-Time PCR with Serotype-Specific Probes for Serotyping of Dengue Virus Infections

Table 4

LOD of the generic real-time PCR^a.

DENV in vitro RNA copies in PCR^a	IC copies in PCR^b	Number positive DENV in vitro RNA (%; mean Cq-value: SD)	Number positive IC (%; mean Cq-value: SD)
2500	500	20/20 (100%; 35.98; 0.99)	20/20 (100%; 33.43; 0.65)
1250	500	12/20 (60%; 36.96; 1.13)	20/20 (100%; 32.84; 0.53)
1000	500	10/20 (50%; 37.33; 0.94)	20/20 (100%; 33.66; 0.53)
625	500	8/20 (40%; 38.72; 1.82)	20/20 (100%; 32.61; 0.59)
312	500	5/20 (25%; 39.17; 2.67)	20/20 (100%; 32.69; 0.34)
0	0	0/20	0/20

^aLOD of the generic PCR was determined by 2-fold dilution series with 20 replicates per dilution of DENV in vitro RNA in the presence of a fixed amount of IC spiked into lysis buffer containing DENV negative human serum as background.
^bnumber of copies cDNA/PCR has been calculated as 1/12.5 of the extracted RNA, assuming 100% efficiency in extraction, reverse transcription (RT) and PCR.
LOD: lower limit of detection; SD: standard deviation.