Table 2.
Comparison of plasma-DNA extraction with MagnaPure and SNAP card technique
| All samples (n = 281) | Week of gestation |
|||
|---|---|---|---|---|
| 7th–13th (n = 28) | 14th–24th (n = 208) | ≥ 25th (n = 45) | ||
| MagnaPure compact | ||||
| DNA concentration, ng/μl (range) | 15.7 (4.9–87.5) | 13.6 (5.8–25.6) | 15.8 (4.9–87.5) | 17.0 (10.1–23.9) |
| Mean number of informative SNPs | 2.6 | 1.7 | 2.8 | 2.1 |
| Mean peak height (SBE) | 1,253 | 998 | 1,269 | 1,308 |
| qPCR (RHD only) Ct value | 36.8 (n = 176) | 37.3 (n = 18) | 37.0 (n = 136) | 35.5 (n = 22) |
| SNAP card | ||||
| DNA concentration, ng/μl (range) | 33.8 (17.1–159.1) | 32.9 (19.6–93.0) | 33.5 (17.1–159.1) | 36.3 (18.1–134.4) |
| Mean number of informative SNPs | 3.7 | 3.3 | 3.9 | 2.9 |
| Mean peak height (SBE) | 1,596 | 1,750 | 1,633 | 1,455 |
| qPCR (RHD only) Ct value | 37.4 (n = 176) | 38.2 (n = 18) | 37.5 (n = 136) | 36.6 (n = 22) |
| Mean fetal DNA yield (% of MagnaPure extraction) | 116.2 (1.4–357.6) | 143.5 (28.0–336.6) | 117.7 (1.4–357.6) | 87.6 (20.6–248.5) |