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Table 4 Overview of the LoB and LoD

From: Development of a highly sensitive and specific intact proviral DNA assay for HIV-1 subtype B and C

Limit of Blank (LoB) on donor PBMCs

LoB = meanblank + 1.645 × (SD blank)

LoB 60 °C = 0.12 + 1.645 × 0.48 = 0.90

LoB 55 °C = 0.34 + 1.645 × 0.80 = 1.66

Limit of detection (LoD) on Gblocks

Copy input

Mean copy output

Standard deviation

Number of repeats

% Positive signals

95% CI

60 °C

6

6.38

3.68

40

97.5

5.24–7.52

5

4.15

2.99

40

92.9

3.25–5.05

4

3.50

2.36

42

90.0

2.77–4.23

3

3.21

2.22

41

95.1

2.53–3.89

2

1.91

1.63

42

83.3

1.42–2.40

1

1.11

1.19

44

61.4

0.76–1.46

55 °C

5

3.56

2.37

44

95.5

2.86–4.26

4

2.46

1.77

44

90.9

1.93–2.98

3

2.28

1.97

44

84.1

1.70–2.86

LoD = LoB + 1.645 × (SD sample 95% positivity)

LoD 60 °C = 0.90 + (1.645 × 3.68) = 6.9

LoD 55 °C = 1.66 + (1.645 × 2.37) = 5.6

  1. The LoB has been determined by using DNA derived from PBMCs of HIV-negative donors. The LoD and the 95% CI of an annealing temperature of 60 °C and 55 °C are calculated by running replicates of Gblocks containing the specific psi and env sequences for 1–6 copies. For 0 copies, the LoB values of DNA derived from PBMCs of HIV-negative donors are depicted
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Virology Journal

ISSN: 1743-422X