Skip to main content

Table 2 Detection capacity of multiplex quantitative PCR.

From: Multiplex quantitative PCR for detection of lower respiratory tract infection and meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis

Oligos for a single target Oligos for three targets Δ Ct Δ copy number (log 10)
DNA standard copy number
of target DNA (number of reactions)
Mean Ct value Mean measured copy
number (log10)
DNA standard S. pneumoniae,
H. influenzae and N. meningitidis
copy number of each target DNA
Mean Ct value Mean measured copy number (log10)   
Spn 10000 (5) 27.7    27.8   0.1  
Spn 2000 (5) 30.2    30.4   0.2  
Spn 500 (7) 32.7    32.4   -0.3  
Hi 10000 (5) 23.8    23.7   -0.1  
Hi 2000 (5) 26.4    26.4   0.0  
Hi 500 (7) 28.6    28.5   -0.1  
Mc 10000 (4) 27.6    27.4   -0.2  
Mc 2000 (4) 30.5    30.0   -0.5  
Mc 500 (6) 32.5    32.3   -0.3  
Spn (23 clinical samples) 27.7 ± 7.6 3.9 ± 1.8   28.2 ± 7.6 3.8 ± 2.0 0.5 -0.1
Hi (50 clinical samples) 24.1 ± 10.7 3.9 ± 2.8   24.7 ± 7.6 3.8 ± 3.0 0.6 -0.1
Mc (8 clinical samples) 22.0 ± 1.9 5.2 ± 0.5   22.2 ± 2.0 5.2 ± 0.5 0.2 0
  1. Ct = Cycle of threshold; Spn = S. pneumoniae; Hi = H. influenzae; Mc = N. meningitidis
  2. Comparison of using PCR reaction mix with a single DNA standard and oligos for one target organism versus triplex DNA target standard and oligos for 3 target organisms.