Development and Validation of an ELISA at Acidic pH for the Quantitative Determination of IL-13 in Human Plasma and Serum
Table 3
Parallelism assessment of IL-13 assay in human plasma under acidic conditions. The accuracy was calculated using the IL-13 concentration determined at dilution 1 : 2 as a reference value. Parallelism was considered acceptable when accuracy was between 70 and 130% for at least 5/6 samples at each dilution.
Dilution
Raw result (pg/mL)
Accuracy (/, %)
Observed ()
Expected ()
Sample 1
1 : 2
0.425
1 : 3
0.250
0.283
88.2
1 : 4
0.195
0.213
91.8
1 : 6
N.C
N.C.
N.C.
Sample 2
1 : 2
1.280
1 : 3
0.760
0.853
89.1
1 : 4
0.525
0.640
82.0
1 : 6
0.362
0.427
84.8
Sample 3
1 : 2
0.745
1 : 3
0.517
0.497
104.0
1 : 4
0.425
0.373
114.1
1 : 6
0.285
0.248
114.8
Sample 4
1 : 2
1.190
1 : 3
0.763
0.793
96.2
1 : 4
0.540
0.595
90.8
1 : 6
0.365
0.397
92.0
Sample 5
1 : 2
1.330
1 : 3
1.020
0.887
115.0
1 : 4
0.830
0.665
124.8
1 : 6
0.553
0.443
124.8
Sample 6
1 : 2
0.270
1 : 3
0.207
0.180
114.8
1 : 4
0.148
0.135
109.3
1 : 6
N.C
N.C.
N.C.
N.C.: value not calculated as being outside the calibration range.
