Article Figures & Data
Figures
- Figure 1.
Modified Levy-Jennings plots for six QC subjects over 188 plates/batches for IGF-I and IGFBP-3 assays.
- Figure 2.
Effects of storage and handling history on IGF-I and IGFBP-3 levels from samples of the NHANES 1988-1994 surplus serum.
- Figure 3.
Distribution of SDs for IGF-I and IGFBP-3 QC samples.
Tables
- Table 1.
Variance components for assays of IGF-I and IGFBP-3 from run-in and main study
(A) Variance components Source* IGFBP-3 Ln IGF-1 Run-in Main study Run-in Main study Between-subject 891,683 834,353 0.0861 0.0884 Between-week 259,217 0 0.0011 0.0006 Between-day 24,617 7,627 0.0012 0.0040 Between-plate 89,176 50,683 0.0035 0.0054 Within-subject 122,571 74,849 0.0150 0.0133 (B) Percent of variance associated with different factors Source* IGFBP-3 Ln IGF-1 Run-in Main study Run-in Main study Between-subject 64.3 86.2 80.5 82.7 Between-week 18.7 0 1.0 0.6 Between-day 1.8 0.8 1.1 3.7 Between-plate 6.4 5.2 3.3 5.0 Within-subject 8.8 14.0 14.0 12.4 NOTE: Day is nested in week and plate is nested in day and week.
↵* Variance estimates obtained with restricted maximum likelihood approach.
- Table 2.
Descriptive statistics for the six QC subjects analyzed in this study
Subject N IGF-I (ng/mL) IGFBP-3 (ng/mL) Mean SD Min Max CV Mean SD Min Max CV A 140 322.3 40.9 201.0 430.5 12.7 2,908.5 363.9 1,641.0 5,139.0 12.5 B 140 324.5 49.8 169.8 413.7 15.4 4,726.5 447.6 2,369.5 5,579.5 9.5 C 125 219.6 38.6 121.9 409.8 17.6 2,838.5 315.0 1,895.5 3,726.5 11.1 D 126 188.0 27.9 103.9 271.8 14.9 4,398.0 393.1 3,463.5 5,881.5 8.9 E 114 250.8 30.9 167.5 321.7 12.3 2,556.2 328.2 1,983.5 3,900.5 12.8 F 114 153.1 22.4 95.0 216.6 14.6 3,005.9 296.6 2,378.5 4,432.0 9.9
May 2007
Volume 16, Issue 5
Volume 16, Issue 5
Serum Levels of Insulin-like Growth Factor-I and Insulin-like Growth Factor-I Binding Protein-3: Quality Control for Studies of Stored Serum
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