Table 13 Assay characteristics compared to human GFAP assays

N4PA

BC-2209

RD192072200R

Stroke Array

152

250

35

N/A

50

12.5

LLOD (pg/mL)

Outcome

0.221

N/A

45

N/A

*50 †30

9

Protocol

2.5 SD above background signal of blank. 2 reagent lots and 3 instruments, 12 runs total.

N/A

3 SD above background signal.

N/A

*2 SD above lowest standard point.

†N/A

2.5 SD above background signal of 16 blank replicates.

LLOQ (pg/mL)

Outcome

0.467

10

N/A

160

N/A

< 24.8

Protocol

Serial dilutions of calibrator assayed in triplicate. 2 reagent lots and 3 instruments, 12 runs total.

Lowest measured concentration of serum pools (n = 7, some spiked) with duplicate CV < 15%.

N/A

N/A

N/A

10 SD above background signal of 16 blank replicates. Lowest measured concentration of plasma specimens (n = 8) with duplicate CV < 20%.

ULOQ (pg/mL)

Outcome

4000

320

25,000

100,000

*150,000

†100,000

> 16,534

Protocol

N/A

Highest measured concentration of serum pools (n = 7, some spiked) with duplicate CV < 15%.

N/A

N/A

N/A

Highest measured concentration of plasma specimens (n = 8) with duplicate CV < 20%.

Intra-assay CV (%)

Outcome

4.2

3.6

5.1

3–4

*1.1–1.9

†0.8–0.62

5.0

Protocol

Within-run CV from 5 days, 2 runs/day, 1 plasma pool/run, 3 replicates/pool.

Within-run CV from 5 days, 1 run/day, 5 serum pools/run, 4 replicates/pool.

Within-run CV from 8 replicates of 2 serum specimens.

N/A

*Within-run CV from 1 run, 4 serum specimens, 21 replicates/specimen.

†Within-run CV from 1 run, 5 serum specimens, 21 replicates/specimen.

Within-run CV from 5 days, 1 run/day, 3 plasma pools/run, 5 replicates/pool.

Inter-assay CV (%)

Outcome

0.0

0.8

5.7

N/A

*2.7–4.2

†1.8–5.9

7.2

Protocol

Between-day CV from 5 days, 2 runs/day, 1 plasma pool/run, 3 replicates/pool.

Between-day CV from 5 days, 1 run/day, 5 serum pools/run, 4 replicates/pool.

Between-run CV from 7 runs, 2 serum specimens/run.

N/A

*Between-day CV from 10 runs, 4 serum specimens/run, 21 replicates/specimen

†Between-day CV from 10 runs, maximum 2 runs/day, 5 serum specimens/run, 6 replicates/specimen.

Between-day CV from 5 days, 1 run/day, 3 plasma pools/run, 5 replicates/pool

Recovery

Outcome

50–120%

N/A

83–115%

N/A

N/A

62–97%^A

86–105%^B

Protocol

Spike 80 and 800 pg/mL into serum (n = 2) and plasma (n = 2).

N/A

Spike 500, 1000, and 5000 pg/mL into serum (n = 3).

N/A

N/A

Spike 100, 1000, and 10,000 pg/mL into plasma (n = 5).

Dilution Linearity

Outcome

102–121%

89–100%

97–121%

N/A

N/A

93–105%

Protocol

Spiked serum diluted 1:4 to 1:128.

Combined clinical specimens with a low-concentration serum pool in different proportions (n = 11)

Serum (n = 3) diluted 1:2 to 1:8.

N/A

N/A

Plasma (n = 3) diluted 1:2 to 1:16.

Supplier

Supplier

Supplier

Posti et al 2017 [47]

*Tichy et al [15]

†Luger et al [18]

[7, 11,12,13,14, 26, 31, 44]

[4, 8, 9, 17, 24, 25, 40]

[6, 10, 11]

[16, 41, 47]

[15, 18]